diseases that cause hyperpigmentation
See your doctor if you have signs and symptoms that commonly occur in people with Addison's disease, such as: 1  Darkening areas of skin (hyperpigmentation) 2  Severe fatigue. 3  Unintentional weight loss.  Gastrointestinal problems, such as nausea, vomiting and abdominal 1  pain. Lightheadedness or fainting.  Salt 1  cravings. Muscle or joint  pains.