Insomnia - inability to sleep; abnormal wakefulness.
causes and risk factors:
A subjective perception of inadequate sleep with complaint of difficulty in falling asleep early morning waking, frequent interruptions of sleep or unrefreshing sleep.
Cause including physical illness, causing pain, breathlessness, stiffness etc, psychiatric problems especially depression and anxiety, Drug induced due to alcohol, caffeine or nicotine and steroids, lesodopa, phenytoin and theophylline, slup aproea, jet lag etc.
Also environmental noise, extreme temperature, change in environment, mental or physical stress. Appears more common in the elderly as also in menopausal females.