The most common signs and symptoms of the disease are: fatigue, hyperpigmentation of skin and mucous membranes, anorexia, nausea, diarrhea, vomiting and muscle weakness.
The most specific symptom of this disorder is fatigue, which at the onset of the disease is sporadic but whose intensity and frequency increases as adrenal function is impaired. This symptom is determined mainly by deficient neuromuscular function which is determined by the following process: the lack of glucocorticoid hormones disturbs the glucidic, lipidic and proteic metabolism; due to the lack of cortisol, the amount of glucose produced from proteins decreases, thus diminishing the muscle and liver glycogen deposit and so, weakness occurs. It also may occur muscular or articular pain.
Although hyperpigmentation may be absent, it is a specific feature of the disease. It appears as a tanny aspect of the skin, even in areas not expose to the sun. The most affected areas are: skin creases, old scars, the areolae, and the mucous membranes. Other disorders that produce skin abnormalities and which may co-exist with Addison's disease are goitre (6%) and vintiligo (3%).
Some patients also have neurological disturbances such as postural dizziness, syncope, the enhancement of hearing and olfaction and reduced sensory modality of taste. They may also have personality changes, mood swings increased irritability and restlessness which may lead to an incorrect diagnosis of neurosis. In 12% of cases it has been observed a decreased tolerance to cold.
Due to the loss of adrenal androgens, axilary and pubic hair may be decreased in women. Amenorrhea may also occur as a result of metabolical disturbances.
Addisonian crisis (adrenal crisis) is a very severe complication of Addison's disease. It represents a rapid intensification of the disease and it is usually triggered by sepsis or by surgical stress. The adrenal crisis signs and symptoms are: severe abdominal pain, profound astenia, severe lower back and leg pain, low temperature or fever (in case the crisis has been triggered by infection), fulminating vomiting and diarrhea (leading to severe dehydratation), confusion or psychosis, convulsions, hypotension, rapid heart rate and loss of consciousness. This is a life-threatening state and immediate treatment is imperative. In all cases the precipitating or the triggering cause must be sought. Delay in diagnosis and treatment can result in poor outcomes.