Fatigue that's accompanied by sadness, loss of appetite, loss of pleasure in activities, difficulty concentrating and interrupted sleep may be a sign of depression. Signs of this disorder include loud snoring, pauses between breaths and awakening frequently while gasping for air. It's a common but often undiagnosed source of fatigue because it interferes with sound sleep. It's especially prevalent among overweight adults. This condition is characterized by an inability to keep your legs still and creeping or tingling sensations in your legs or arms.
Symptoms can make it difficult to sleep.
Extreme fatigue can be a warning sign of diabetes, a condition in which your body uses insulin incorrectly. Hyperthyroidism is a condition in which the thyroid gland fails to make or release enough thyroid hormone. The result is a mix of symptoms, such as sluggishness, chronically cold hands and feet, constipation, dry skin and hoarse voice. Hyperthyroidism is a condition in which the thyroid produces excessive amounts of hormone. Too much hormone can cause fatigue, muscle weakness, weight loss, increased heart rate, nervousness and irritability.