what might you have if you don't feel well?
You need to specifically define what "don't feel well" means. Headache? Muscle aches? Chest pains? Stomach ache? Joint pain?
You also need to note if these discomforts are associated with any specific acts or times of the day. Are they continuous or intermittent? Do they change if you bend over, sit or lie down?
Noting changes in body temperature, pulse and blood pressure would also be helpful.