Fatigue, fuh TEEG, is another name for tiredness. People often say they are "fatigued" when they feel tired. If we work hard, play hard, or go without rest or sleep, we expect to feel fatigued. In such cases, fatigue is normal. We know from experience that this feeling will disappear after we rest. But sometimes fatigue is a symptom of illness. Physically ill people often become fatigued after even a slight amount of work or exertion. Such people need a great deal of rest, often much more than they would need if they were well. Doctors have found that fatigue occurs frequently during many kinds of illnesses.