Want to sleep or too much sleep also becomes the cause of the disease. Sleep is necessary, absolutely essential for health. That is why one should avoid sleeplessness as well as oversleeping. One must sleep moderately. Ayurveda also mentions the harmful effects of over-sleeping. It forbids sleeping during the day (diva-shayana). According to Ayurveda, there is a link between sleep and phlegm. Thinking about it from the point of view of yoga, we come to the conclusion that over-sleeping shortens one's life. The frequency of breathing increases during sleep. The person, who oversleeps, reduces his vital energy. Keeping awake till late is also the cause of the diseases.