What is fatigue?

What is fatigue?

Fatigue can be confused with tiredness. Everyone gets tired. It's an expected feeling after certain activities or at the end of the day. Usually, we know why we're tired, and a good night's sleep will solve the problem.

Fatigue is different. Fatigue is a daily lack of energy — an unusual or excessive whole-body tiredness that is not relieved by sleep. It can be acute (lasting a month or less) or chronic (lasting from one to six months or longer). Fatigue can have a profoundly negative impact on a person's ability to function and quality of life.