Dear Doctor,

Are there any dangers of sleeping for long hours? If so, what is the recommended time one should stay in bed? Rachel

Dear Rachel,

Sleep is necessary for the body to provide complete physical and mental relaxation. It helps in rejuvenating the fatigued tissues, helps in physiological processes like digestion and hormonal balance. But excess of sleep is also not good for human health. Occasionally every individual sleeps for long hours when exhausted, as after a long journey or working over night. One can sleep more due to sleep disorders like obstructive sleep apnoea and narcolepsy, or due to medicines like anti allergy or sedative/ tranquilizer. But apart from those situations, excess sleep is not healthy nor considered normal.

Excess sleep can lead to obesity, which is a risk factor for several diseases in the body like hypertension, diabetes, heart problems and osteoarthritis. One does not feel fresh after sleeping much. It gives rise to feeling of laziness, heaviness over the body and malaise. People sleeping much have demonstrated symptoms of anxiety and low energy levels, situations which probably creates need in them to sleep more.

Some studies have linked excess sleeping to depression. Over a time, those sleeping much can develop some brain dysfunction like loss of memory or reduced alertness. Excess sleeping has also been implicated in causing infertility. Though precise reason is not known, it is said to be due to disruption in the body’s normal biological clock, thus disturbing the balance of hormones.

7-8 hours of average sleep with some variations, is normal for an adult. The hours vary with age, being more in children, teenagers and reduce with advancing age.