Being tired and sleepy all the time. It is a common symptom of many medically identified disorders. The patient might get more than enough sleep (up to 10 hours) but remain drowsy. It forces the person to have more sleep, but oversleep does not help. It may only worsen other health conditions and overall dynamics. There are two types of fatigue: physical and mental. In the case of cancer, the patients experience both. First, they start forgetting things and having difficult times communicating with others. Second, they feel like laying down and taking a nap.