The symptoms of Addison's disease typically emerge gradually over several months. In some cases, the progression of the disease is so subtle that symptoms may go unnoticed until a stressful event, such as an illness or injury, exacerbates them. Common symptoms include extreme fatigue, weakness, abdominal pain, muscle and joint aches, salt craving, dizziness, nausea, vomiting, loss of appetite, and weight loss. Clinical signs of the disease include skin darkening, particularly on the head, neck, back of the hands, and mucous membranes (especially the gums), low blood pressure, reduction of underarm and pubic hair in women, and decreased libido.