What causes fatigue had my thyroid check in it is good?

Multiple causes: Deconditioning, poor diet, depression, infections, inflammatory conditions, anemia, cardiac and respiratory disease.

Many causes: Fatigue is one of the commonest symptoms for which physicians are consulted and has many causes. Among them are lack of adequate sleep, anemia and low iron stores, chronic infections and inflammatory conditions, depression, low cardiac output, hormonal deficiencies, and certain medications. Obviously one office visit and a simple blood test is not enough to properly evaluate this complaint.