Addison's Disease

Definition (thanks to Medpedia): 

"Addison disease is an uncommon, but potentially catastrophic endocrine disorder affecting the adrenal glands. In Addison disease, the adrenal glands, which sit above the kidneys, do not produce enough of the hormones cortisol and aldosterone."

Cortisol:

Cortisol belongs to a class of hormones called glucocorticoids which affect almost every organ and tissue in the body. It plays a vital role in virtually all aspects of the body, from quality of sleep, mood and memory to connective tissue turnover and muscle integrity. Cortisol is most known for the role it plays in the body's ability to respond to stress, however. 

Cortisol also

• Helps maintain blood pressure and cardiovascular function,
• Helps slow the immune system's inflammatory response,
• Helps balance the effects of insulin in breaking down sugar for energy,
• Helps regulate the metabolism of proteins, carbohydrates, and fats, and
• Helps maintain proper arousal and sense of well-being.

Aldosterone:

Helps maintain blood pressure and water and salt balance in the body by helping the kidney retain sodium and excrete potassium. When aldosterone production falls too low, the kidneys are not able to regulate salt and water balance, causing blood volume and blood pressure to drop.

The Signs and Symptoms of Addison's Disease:

• Chronic, worsening fatigue
• Muscle weakness
• Loss of appetite
• Weight loss
• Nausea
• Vomiting
• Diarrhea 

Less common symptoms include:

• Low blood pressure that becomes lower upon standing, causing dizziness or fainting
• Hyperpigmentation (or dark tanning) covering exposed and nonexposed parts of the body. This is most visible on scars; skin folds; pressure points such as the elbows, knees, knuckles, and toes; lips; and mucous membranes
• Irritability and depression
• Craving salty foods
• Hypoglycemia (low blood sugar) - more severe in children than in adults

Addisonian Crisis or Acute Adrenal Insufficiency:

If symptoms go unrecognised and the condition is left untreated or if an Addisonian experiences a stressful event or accident, the individual may go into an Addisonian Crisis. Symptoms of this condition (which can be fatal) include:

• Sudden penetrating pain in the lower back, abdomen, or legs
• Severe vomiting and diarrhea
• Dehydration
• Low blood pressure
• Loss of consciousness