01 · Definition
What is insomnia?
Lying awake for hours, waking in the night, or feeling tired after sleep often reads as insomnia: difficulty falling asleep, staying asleep, or both.
Insomnia is defined by the quality of your sleep and how you feel after sleeping. Chronic thin sleep may contribute to wider health problems. If you feel drowsy and tired during the day even after about eight hours in bed, you may still be experiencing insomnia.