Jethalal S. Zaveri
We are subjected to continual changes in the conditions of the external environment—light and darkness, heat and cold, humidity and dryness. We have mechanisms for maintaining a relatively constant internal environment, despite changes in the external world. For instance, our body temperature is kept constant within a relatively narrow tolerance, in spite of wide fluctuations of the external conditions. As we have seen in the previous chapter, chemical composition of the body fluids is well-controlled too.
Homeostasis is the central theme of the physiologists' studies. In a sense, virtually everything in this book relates to homeostasis in one way or another, it is not a static condition but a dynamic equilibrium, a matter of continual adjustment for maintenance of equilibrium between the organism and the environment.
Normal values or normal ranges of values of various body-indices given in this book are characteristics of the healthy body. Abuses to which we subject our internal organs result in their dysfunctions and lead to the disorders of the system with which they are associated. Homeostatic mechanisms may become less efficient. The body temperature may rise, or specific components of the blood may be higher or lower than normal. Consequently body defences lose their normal efficiency; body indices deviate from the normal and give indication of disease. Such deviations are clinical clues to the diagnosis of diseases. Restoration of homeostasis is essential to life and health.
In this chapter we shall deal with some of the major disorders of various systems.
I. Disorders of Circulatory System
Blood Clotting (Abnormalities)
The organs and systems of the body are intricately interrelated into a smoothly functioning whole. But a disorder in one part can have far-reaching and sometimes unexpected effects on other organs and systems. Thus abnormalities of blood clotting can be caused by defects or damage to a variety of organs. For example, liver disease may give rise to clotting abnormalities that may result in severe or even fatal blood loss. Vitamin K, that may be obtained in the diet and is also synthesized by the bacteria that live in the intestines, is essential too. A heavy course of antibiotic might cause a deficiency by wiping out the intestinal flora together with the pathogens. Bone marrow damage also produces a failure of the normal clotting mechanisms. When the number of blood platelets fall below about 70,000 per cubic mm. of blood, excessive bleeding occurs. Each time a tiny capillary ruptures, blood escapes out into tissues. Damage to the bone marrow by drugs or irradiation and pernicious anaemia can cause this disorder.
Another disorder caused by a deficiency of one or more of the blood clotting factor is haemophilia or "bleeder's disease". Normally a bruise or a cut is a minor incident, quickly healed and forgotten. But a haemophiliac could literally bleed to death with a 'minor' cut. It is a hereditary disease and occurs far more often in males than in females. This disease probably had a major effect on the course of world history: the only son of Czar and Czarina who was a haemophiliac set in motion a chain of events that led to the Russian revolution. Prophylactic treatments with antihaemophiliac factor (AHF), extra-ted from stored old blood, can in many cases permit haemophiliacs to lead a relatively normal life.
Haemorrhage is the escape of blood from the blood vessels. Uncontrolled bleeding is a serious threat to life. As a first-aid measure, excessive bleeding is most effectively controlled by direct pressure at the site of the injury. Gauze applied over the bleeding surface can help by promoting the breakdown of platelets, initiating the reactions of clotting. The body has an assortment of mechanisms for compensating a moderate loss of blood (e.g. loss by donation). The capacity of the system is decreased by vaso-constriction. The liver and spleen contract and sent their blood reserves into the veins. Tissue fluids diffuse into the vessels. Thus plasma volume is regained in a few hours; plasma proteins are restored more slowly and formed elements (viz. red blood-cells, white blood-cells, platelets) may take a month or more. In more severe haemorrhage, symptoms of shock may develop: the pulse rapid and weak, the skin pale, clammy and cold. If more than 30 to 35 percent of the total blood volume is lost, the body cannot compensate rapidly enough. Unless a blood transfusion is administered quickly, the victim may die.
Fatal heart-attacks are caused by a blood clot lodging in the coronaries of the heart, blocking flow of blood and causing irreparable damage to the heart muscle. Normally blood clotting occurs when a blood vessel is damaged, to stop the loss of blood. Sometimes, however, clots form inside an undamaged blood vessel. The clot is called thrombus and partial or complete blocking of a blood vessel is called thrombosis. A travelling thrombus is called an embolus. Ultimately, if the embolus reaches a vessel that is too narrow, it may plug the vessel. The amount of damage caused by an embolus depends on the region in which it lodges. A coronary embolus can cut off the supply of oxygen to the heart and cause a heart-attack. An embolus carried to the blood vessels of the brain may result in a stroke causing a loss of part of the mental function or death.
What causes clot-formation inside a blood vessel? The introduction of any foreign substance into the blood stream - even a large air bubble introduced during the improper administration of an injection—might provide a nucleus for platelet congregation and result in thrombosis. Prolonged bed rest—in operation and illnesses—in which there is a pooling of blood in the vessels of extremities, can also result in clot-formation. Eventually the clots break loose and may be carried to the pulmonary arteries. Early ambulation is, therefore, recommended in operations.
Fortunately, the body has an assortment of natural mechanism for coping with the danger of thrombosis. First of all, the inner surface of the blood vessels is extremely smooth as well as coated with a very thin film of a negatively charged protein substance which repels the clotting factor. Antithrombin, normally present in the blood, also acts to remove thrombin from the blood and inhibit clotting. Helapin, a powerful anticoagulant is secreted into the blood by most cells of the connective tissues around the capillaries. It prevents clotting in several ways. Dicumarol and hirudin are substances not found in the body, but can be administered to reduce the risk of thrombo-embolism.
If an important blood vessel of the body is blocked (by a clot), the obstruction deprives body-tissues of vital supplies of oxygen and nutrients. Poisonous waste products build up in the starved tissues and if they are part of key organ, the damage that results may lead to death. Thus clearing a clot may literally be a race against death. In a healthy body clot formation and dissolution go hand in hand to some extent. One of the plasma proteins, when activated, resembles the enzyme trypsin. It literally digests a blood clot, dissolving it away.
Atherosclerosis and Arteriosclerosis
Atherosclerosis, the building up of fatty deposits in the artery walls, narrows the blood-vessel-lumen (i.e. the interior capacity), raising the blood-pressure, forcing the heart to work harder against the increased peripheral resistance and increasing the possibility of thrombosis. A progressive deposition of fatty deposits (mainly cholesterol) in the inner layer of the arteries produces hardening of the arteries - arteriosclerosis. Later on, fatty deposits calcify and reduce the elasticity of the blood-vessel promoting hypertension. The roughened surfaces of the plaque may rupture and disintegrate fragile platelets and initiate the clotting mechanisms. Normally the blood flows rapidly enough to disperse the clotting factors, but atherosclerosis can slow down circulation sufficiently to permit clot-formation to begin. Three causes have been identified for the plaque-formation—(i) fatty diet, (ii) high sugar intake and (iii) hypertension.
Arteriosclerosis or "hardening of the arteries" is commonly considered a disease of old age, but it may begin in childhood and show no symptoms for many decades. The earlier condition of soft fatty deposits is referred to as atherosclerosis as mentioned above. When the deposits classify and harden, they reduce the elasticity of the arteries. Besides the blood clot which may be formed, the lipid core of the plaques themselves may also break away and be carried through the blood stream as an embolus.
Hypertension
A resting systolic blood-pressure above 140 mm of mercury is classified as hypertension (high blood-pressure). Some of the cases are found to be the result of specific disease or disorders, such as arteriosclerosis, kidney-disease etc. But in vast majority of cases, no definite cause can be discovered. When the blood-pressure is high, the heart must work harder to pump blood and eventually it enlarges; and if it cannot meet the demands placed on it, it may fail. Hypertension also sets up a vicious cycle involving the kidneys. When the blood-supply to the kidneys is reduced due to narrowing of the arterioles, the kidneys react by secreting their hormone renin which raises the blood-pressure still further and compounds the problem. A weak spot in the artery-walls anywhere in body may cause it to balloon out or even rupture.
Probably tens of thousands of lives can be saved each year if every one had his or her blood-pressure checked regularly. About one sixth of the population has high B.P., but many are completely unaware of this condition. They stand a much higher than average risk of suffering heart-attack. Early detection of high blood-pressure can bring it under control.
Vasodilation (widening of the diameter of the blood-vessels as a result of the relaxation of the vascular smooth muscles) decreases the blood-pressure. People can be taught to lower their blood-pressure by learning the technique of relaxation and the use of bio-feedback equipment. In time, the person is gradually able to lower the B.P. at will.
Anaemia is characterised by deficiency of haemoglobin due either to a decreased number of red blood cells or to an insufficient amount of haemoglobin per cell. It, can be caused by a variety of factors. The average red blood cell lives only about 120 days. Thus, an entire new supply of functioning red cells, each with the appropriate cargo of haemoglobin must be constantly produced. If insufficient raw materials are available, and if blood cells are lost faster than new ones can be produced, anaemia can result.
Vitamin B12 is a key compound in process of DNA formation and is essential in the maturation of the red blood cell. It is supplied by a well-balanced diet. If it is lacking in the diet or is not properly absorbed, anaemia can result.
Radiations, certain industrial chemicals and some drugs may damage the bone marrow and prevent it from forming new red cells.
II. Disorders of the Respiratory System
The respiratory tract is one of the gateways into the body. Despite the formidable array of defences, it is vulnerable to a variety of illnesses caused by the insidious onslaught of air-pollution and other environmental dangers. Besides, a surprising number of people choke to death, because an insufficiently chewed piece of food is mis-swallowed and it blocks the trachea.
Modern immunization programmes, increased standards of sanitation and antibiotics have brought freedom from fear of many diseases that used to be scourges. Infections such as diphtheria and whooping cough, which used to kill large numbers of young children, have now become rare. The incidence of tuberculosis has dropped sharply and the pneumonia death rate has been lowered drastically. On the other hand, certain factors in the modern environment are promoting a rise in respiratory (and other) ailments that were either non-existent or only minor problems in the past. The effluvia of factories and vehicles and the personal air-pollution by cigarette-smoking has brought a rise in lung-cancer and emphysema. Air-conditioning can dry the mucous membranes of the respiratory passages making us more vulnerable to infection.
Asthma
Asthma is a special type of allergic reaction that can be terrifying to the patient. The condition is characterized by edema (excess fluid) in the bronchioles, secretion of thick mucus and bronchial spasm. It results in laboured breathing and wheezing. Outflow of the air is obstructed more than the inflow and the lungs become distended. Asthmatic attacks may be caused by pollen and/or food sensitivities. A psychological component may also be present since attacks are often precipitated by an emotional crisis.
Bronchitis is a chronic dilation of the bronchi, characterized by spasms of coughing and production of large quantities of pus-containing sputum. Dyspnea[1] and fever are common symptoms. Fatigue, malnutrition and exposure to cold can contribute to the onset of this disorder.
Common Cold
Common Cold is an inflammation of the mucous membrane of the nose. Symptoms include an actue congestion of nose and increased secretion. The swelling of the membrane and accumulated secretions make breathing difficult. Fever and headache may also occur. Colds are caused not by one or two specific pathogens but by more than 100 different viruses. And the vaccines provide protection only against a few of them. Children upto the age of six are most susceptible to colds while people over the age of 45 seldom catch cold, probably as a result of accumulated immunity to cold viruses.
Colds are usually relatively mild illnesses that run their course in about a week. However, the infection may spread producing sinusitis, conjunctivitis and middle ear or mastoid infection. Besides, they lower the body defences and may prepare the way for bronchitis, meningitis or pneumonia. The use of a large dose of vitamin "C" may prevent the cold.
Influenza
Influenza is caused by a group of viruses and is highly contagious. Common symptoms are fever, body aches, general weakness and inflammation of the mucous membranes of the respiratory tract. Outbreaks periodically sweep through the world. The fact that there are several types of viruses and that they have exhibited a great tendency to mutate into new violent forms means that immunity from the disease is difficult.
Pneumonia
Pneumonia is an acute infection in which lung tissue or the walls of the bronchi are inflamed. It is usually caused by a bacterium, pneumococcus. (A viral pneumonia is similar to influenza). Chills, chest-pain, fever, coughing and delirium are frequent symptoms. It occurs most often in young children and in the aged. Now that effective antibiotics are available, this disease is much less feared.
(Pulmonary) Fibrosis
In this disorder, the normal lung-tissue is replaced by fibrous tissue. The elasticity and capacity of the lungs are reduced and respiration is difficult. Chest-pain, a dry cough and fatigue after slight exertion are common symptoms. Later, breathing becomes more laboured. Silicosis and black lung are fibrosis of the lungs caused by inhalations of air laden with silicon dioxide or carbon particles in the mines.
Emphysema
Emphysema is one of the fastest growing diseases in the modern world. It is a disease of old age and results from the effects of smoking and air-pollution. In this disease, walls of the alveoli are atrophied and thinned; bronchioles are obstructed and total surface of the respiratory membrane is greatly reduced, sometimes to less than one quarter of the normal value. The capillary bed around the alveoli is also reduced. All these changes are irreversible and lead to increasing dysnea. The disease progresses over many years and the chronic straining to draw breath produces a barrel shaped chest and distended lungs.
Lung Cancer
The result of smoking that has most captured the public imagination is the development of carcinoma of the lung or lung cancer. This is a neoplastic growth, malignant and often fatal, which is more than 20 times as prevalent in smokers. As the malignant cells multiply, they suffocate the normal cells and destroy tissue. Removal of affected segments or of an entire lung by surgery is often resorted to as treatment.
Tuberculosis (T.B.)
Tuberculosis is sometimes called consumption. About half of us become infected with this disease at one time or another, but when the general health is good, the body's defences can usually contain the invading pathogens called tubéreuse bacilli. They invade the lungs and the infected area becomes walled off by fibrous tissue forming "tubercle". Sometimes the bacilli spread producing tubercles in various sites. The reduced vital capacity, decreased membrane-area and increased membrane-thickness make breathing progressively more difficult and less effective. A diseased lobe may be removed surgically. Effective specific drugs such as streptomycin are now available and the disease is much less feared now than before.
III. Disorders of Digestive System
With some thirty feet of alimentary canal, it is no wonder that disorders of the digestive system are among the most common causes of visits to doctors.
Antacids and laxatives are, perhaps, one of the most widely used medicines sold over the counter. In many cases, however, these are unnecessary and may even be harmful.
Indigestion
Indigestion or Dyspepsia is a vague term used loosely for a variety of digestive system. Any one or more than one of the following conditions may be the cause of disorder:
Spasm of the esophagus
Inflammation of the stomach-wall
Peptic ulcer
Cancer of the stomach
Gall-bladder diseases
Intestinal disorder
Emotional upsets.
Obviously no one medicine can be a panacea for such a diverse assortment of ills. Persistent indigestion should be a warning signal to search the root of the disorder. Chewing a few antacid tablets neutralises the gastric acid. But, in fact, the presence of a fairly strong hydrochloric acid is essential for proper stomach function. Indeed, inadequate production of this acid due to atrophy of acid producing mucosa in the stomach is a common cause of gastritis and chronic diarrhea. This responds well to a dose of dilute hydrochloric acid solution after meals.
Food-poisoning
Food-poisoning is the result of eating foods or drinking water contaminated with bacteria or their toxins or with other poisons. The contamination may be introduced by the food-handlers who might carry the germs in their nose, hands, nails etc. This illness is characterized by various combinations of nausea, vomiting, abdominal cramps, diarrhea, fever and prostration and usually lasts for 12 to 24 hours. High standard of sanitation, particularly after excretion, proper cooking, adequate covering and refrigeration of foodstuffs prevent most bacteria-caused food-poisoning.
Constipation
The failure to have a regular bowel movement every day is viewed with alarm and quickly dosed with laxatives which when taken habitually can decrease the tone of the large intestine and set up a vicious cycle producing constipation. A frequent cause of the disorder is the habit of tailing to respond to an urge to defecate, putting the action off until a more convenient time. The excessive resorption of water from the feces that occurs during constipation produces large, hard fecal masses that are difficult to pass. The straining that is necessary to eliminate them may give rise to haemorrhoids and anal fissures, which in turn cause pain and bleeding in later defecations promoting further constipation. Fruits, vegetables and whole grain cereals which contain a considerable amount of indigestible fibre, have a stimulating effect on the bowel. Fats may also stimulate bowel function; undigested fats have a lubricating effect, while partially digested fats are mildly irritating to the intestinal walls and stimulate peristalsis.
Diarrhea
Diarrhea is an excessive elimination of semi-fluid feces. It may be the result of an infection in the gastro-intestinal tract or of excessive parasympathetic stimulation of large intestine. When infected, the irritability of the inflamed mucosal lining promotes peristalsis, sweeping the intestinal contents out of the body faster and helping to get rid of the infection. But this protection mechanism, if prolonged, may cause harm by producing dehydration and decreasing the absorption of needed nutrients. The other form of diarrhea is commonly experienced in times of stress such as in a student during an examination.
Many people neglect a simple but valuable means of monitoring their health; observation of the appearance of the stools. Many disorders of the digestive tract show up in the changes in the consistency and general appearance of the stools. A disorder of the liver and biliary system may be reflected in clay-coloured stools, for the normal colour is imparted to feces by the bile pigments. Bleeding from the upper part of the tract results in black tarry-looking stools. Red streaks are an indication of fresh blood which may come from haemorrhoids or from cancer of the rectum. In parasitic infections eggs, segments or whole worms may be present in the stools.
Dental Caries, Pyorrhea
Tooth-decay is a gradual disintegration of the enamel and dentin caused by acid producing bacteria. An inflammatory infection or degeneration of the gums and cementum may lead to loosening and loss of teeth. Cause include poor oral hygiene, local irritants such as cigarette smoke, allergies and vitamin deficiencies. Proper washing of the mouth and teeth after each meal and at bed time would go a long way to prevent the disease.
Hiatus Hernia, Heartburn, Esophagitis
The opening in the diaphragm, through which the esophagus enters the abdominal cavity and joins up with stomach, is called hiatus. This enlargement of this opening is hiatus hernia. A portion of the stomach may then protrude upward alongside the esophagus through the enlarged opening. Highly acidic stomach contents may regurgitate into the esophagus, particularly when one sleeps or lies down horizontally or when stomach is full, causing burning sensation of the lining of the esophagus. This is called heartburn, which has nothing whatever to do with the heart. Frequent irritation of the esophagus lining produces inflammation, bleeding and ulcers. Pain, a burning feeling, difficulty in swallowing and in breathing are symptoms of esophagitis. Hyperacidity without hernia may also cause heartburn and corrosion of the esophagus lining, such persons are advised to sleep with their upper trunk raised, to prevent regurgitation of the acid. It would also be advisable to avoid heavy meals in the evening and avoid acidity-producing foods such as tomatoes, strong tea or coffee, deep fried foods etc.
Ulcers and colitis
The region of the duodenum near the pylorus is a frequent site of ulcers. The formation of ulcers in the stomach occurs most often on the posterior wall at the pyloric end. Those ulcers are caused by an over-production of gastric acid which eats a hole in the stomach-lining or duodenum. They are characterized by burning pain. Normally alkaline digestive juices from gall-bladder and pancreas neutralise the stomach-acid as it enters the duodenum. But if the acid is too strong to be neutralised, corrosion and ulcers will result. Colitis is inflammation of colon (large intestine). It may be accompanied by ulcers (ulcerative colitis).
Haemorrhoids (piles), Fissures, Fistula
Haemorrhoids or piles are varicose veins in the anal canal which may become filled with blood clots thrombosed causing pain, bleeding and protrusion. Fissure is infection of small crypts in the tissues adjacent to the anus. It can lead to an ulcer of the anal canal which appears as a crack in the skin at the anal margin and produces pain on defecation. The infection may spread through the wall of the anus producing an abscess, which may burst through either internally or externally, forming a chronically discharging fistula. Chronic constipation is the most frequent causes of these disorders.
Cirhosis, Hepatitis and Jaundice
These are diseases of the liver. Cirhosis is a degenerative disease, caused by chronic overconsumption of alcoholic drinks progressively interfering with its function. Hepatitis is an inflammation of the liver caused by viral or bacterial infection transmitted through contaminated food or water. It is also caused by transmission of viruses from infected person through blood transfusion. It may be accompanied by jaundice, fever and enlargement of the liver. Jaundice is a yellowish coloration of the skin and mucous membranes due to the presence of bile pigments in the circulation. When the liver or biliary apparatus is diseased, these pigments enter circulation instead of being eliminated through the intestines.
IV. Disorders of the Muscles
Spasms
Sudden involuntary and painful muscle contractions are the commonest disorders of the muscular system. Backaches are spasms of the muscles in the lumbar region which follow stress or strain. Stiff-neck involves spasms of the neck-muscles on one side. When a spasm is prolonged, it becomes a cramp. Spasms may occur not only in skeletal muscles but in smooth ones as well.
Contracture
Contracture is a painful condition in which muscle-fibres are shortened in the resting position. It may result from strenuous exercise (muscle fatigue), or from long periods of inactivity, when the muscles do not receive sufficient exercise. Bed rest, for example, may cause the muscle-fibres to adjust themselves to a shorter length, corresponding to a flexed limb, and then they must be painfully and patiently exercised to be lengthened again.
Polio
Poliomyelitis (Polio) was one of the most dreaded diseases of childhood for many years. It sometimes killed but more often left its young victims crippled for life with paralyzed limbs and withered muscles. The development of effective vaccines against the polio virus has nearly wiped out the disease. Parents are advised to get their children immunized against polio in good time to prevent the onslaught of the disease.
For an understanding of such disorders of the muscular system, the following concept is of key importance. The functioning unit of a muscle is not the individual muscle-cell but rather the motor unit—the combination of a motor nerve and the muscle fibres that it innervates. Anything that damages either the muscle or the nerve may result in a loss of muscle-function. Thus polio is not a disorder of the muscles in the first place, but a disease of the nervous system in which the virus infection can destroy the neurons. The muscle atrophy (wasting or withering) that often follows the disease is a result of the disuse of the muscle innervated by the damaged neurons or controlled by a damaged centre in the brain stem. The treatment includes regular exercising of the affected muscles.
Atrophy, Hypertrophy and Dystrophy
Muscles tend to atrophy (waste away) with disuse - either in paralysis or due to continued inactivity. When muscles are subjected to prolonged vigorous contractions, the opposite occurs. They hypertrophy i.e. grow larger. As far as the skeletal muscles are concerned, gradual enlargement is not a disorder but a positive change making them stronger and more effective. The key to body-building is to progressively increase the load on the muscles; regular exercise will not produce hypertrophy, if maximum contractions are not involved. The aim of exercise is to condition the muscles and keep them ready for use and not to tire them.
Hypertrophy is a pathological condition for the heart-muscle. Heart tends to enlarge when it is overworked, e.g. when arteries are clogged with fatty deposits. The resulting increased force of contraction may cause great discomfort.
Two rather mysterious diseases have become a source of anxiety lately. These are dystrophy and myasthenia gravis. Evidence indicates that these may be autoimmune diseases.[2]
Muscular Dystrophy is a tragic disease in children in which a normal child suddenly becomes clumsy, falls frequently and then progressively loses the use of muscles, thus becoming entirely helpless. The muscles appear enlarged due to large fat deposits while the actual fibres atrophy and the contractile function becomes ineffective.
In myasthenia gravis, the skeletal muscles become extremely weak. Facial muscles are first affected and the condition spreads to other muscles until victim is incapacitated.
V. Disorders of the Joints
The movements of the elderly people may be accompanied by clearly audible clicks, snaps and creakings (hence the cliche "creaking joints"). Degenerative changes in the joints, that develop with age, include a reduction of the secretion of lubricating synovial fluid, replacement of flexible cartilage by unelastic bone, and the formation of bony spurs around joints, which make movements quite painful. In addition, the joints, at any age, are vulnerable to a variety of injuries and ills.
Sprain, Dislocation, Fracture
Sprain is the injury caused by a sudden wrenching of a joint which may tear or stretch its attachments. It is accompanied by swelling, redness and pain.
Dislocation, a more serious condition than a sprain, is a displacement of one of the bones or an internal derangement of the parts. The shoulder and knee are most vulnerable to this disorder. A shoulder dislocation can be corrected by pulling the arm away from the trunk and rotating it suitably. Most common injury to the knee is a crushing or tearing of one of the cartilages. The condition is extremely painful and the knee may have a tendency to lock suddenly. Removal of the damaged cartilage is often the only effective treatment. (The knee can function more or less satisfactorily even without the cartilage). Foot-ball players and other athletes may acquire a "trick knee" by tearing the ligaments that lash the bones together. The knee may unexpectedly give way. A flexible (elastic) bandage may be used to provide support.
A fracture is the breaking or cracking of a bone. If the skin is unbroken, it is a simple fracture. If the broken ends of the bone protrude outside, it is a compound fracture. In a comminuted fracture the bone is splintered into small fragments.
Herniated Disc (Slip-disc)
Between each pair of vertebrae there is an intervertebral disc, a compressible, cushion-like pad composed of tough fibrous tissue and eartilage and filled with a protein solution. Damage to the surrounding tissues may cause disc to bulge or slip out of its normal position, and cause back-pain. If the disc presses on the sciatic nerve, pain in the legs (sciatica) will also be experienced. Bed-rest and painkillers are generally prescribed. Remedial exercises may also be used. Regular practice of suitable postures and exercise can prevent the recurrence.
Arthritis, Rheumatism, Rheumatic Fever
Arthritis—an inflammation of the joint, is probably the most widespread crippling disease. Fifty varieties are known; the most common are: osteoarthritis, rheumatoid arthritis and gouty arthritis. Osteoarthritis is a degenerative disease, which occurs in middle and old age. The constant wear and tear on weight-bearing joints (e.g. knees) produces a softening thinning and ultimate disintegration of the joint cartilages. Increased function, due to reduced lubrication, irritates the periosteum, stimulating proliferation of bony-growths on the joint surfaces.
Rheumatoid arthritis results in fusion of the bones of the joint and a total loss of mobility. Its cause is still unknown. It begins with the inflammation and thickening of the synovial membrane and tissue which damages the joint cartilage. Tough fibrous material, then, limits motion in the joints. Ultimately the fibrous tissue may become calcified and converted to bone and then fuse together.
Gout is characterized by an increase in the uric acid level of blood and the formation of deposits of urates in the joints. Inflammation and damage to the particular cartilages result.
No cure for arthritis has yet been found. However, considerable progress has been made in the surgical repair of arthritic joints.
Rheumatism is a common, rather loosely used term for an inflammation of the fibrous connective tissue. The affected joints become tender and stiff, and the victim's movements become limited and painful. The fibrositis may travel from one joint to another. Fortunately there is no permanent damage to the joints and recovery can be complete. In a related condition e.g. when tendons of the hand are affected, the hand may become locked into a claw like position, with the patient unable to extend the fingers.
Rheumatic fever is a bacterial disease caused by streptococcus pyogenes. The initial symptoms involve the joints. It begins with a sudden intense inflammation of the synovial tissues, tendons and other connective tissues around the joints, accompanied by fever and pain. After a time, the pain and inflammation of the joints may subside, but the disease may cause permanent damage to the heart-valves which is later manifested as rheumatic heart disease.
