Depression and Anxiety
While there can be underlying causes of depression and anxiety such as anemia and other vitamin and mineral deficiencies, people sometimes suffer from these conditions for other, perhaps unknown, reasons.
If you’ve checked everything and nothing is showing, ask a professional if you have depression or anxiety (or both).
Anxiety causes fatigue by preventing a good night’s sleep, and depression sometimes makes you want to sleep away from your problems, however long you sleep.
Chronic Fatigue Syndrome
Another disease that can cause fatigue is CFS. It’s right in the name. There could be many causes of CFS that we do not yet know about. But it is a real medical condition that is often characterized by fever, body aches and prolonged exhaustion.
This condition sometimes occurs after you think you have recovered from another viral infection. It is very difficult to diagnose and is only given after a thorough examination to rule out other possibilities. But it is a real disease that can be taken care of and treated.