A good night’s sleep is essential for your health, providing rest and restoration for the mind and the body. Insomnia, also known as sleeplessness, is a common sleep disorder where you have trouble falling asleep, staying asleep, or waking up too early, and it interferes with your daytime functioning in some way. It affects both men and women, although females and the elderly are typically affected the most. The condition can be short-term (acute), long-term (chronic), or it may come and go.