What are the key symptoms of Addison's disease?

The key symptoms of Addison's disease include fatigue, weight loss, low blood pressure, and darkening of the skin due to melanin deposition. Addison's disease, also known as primary adrenal insufficiency, occurs when the adrenal glands do not produce enough hormones, particularly cortisol and aldosterone.

Fatigue is a common symptom as the body struggles to maintain normal functions without sufficient cortisol, which is vital for energy metabolism and response to stress. Weight loss occurs partly due to decreased appetite and the body's inability to manage blood sugar levels effectively. Low blood pressure is often seen because of inadequate aldosterone secretion, which regulates sodium and fluid balance. The darkening of the skin is attributed to increased production of melanocyte-stimulating hormone (MSH), which can be elevated when there are low levels of cortisol.

This set of symptoms helps differentiate Addison's disease from other conditions where symptoms such as high blood pressure and weight gain are present, which are more associated with excess cortisol production, as seen in conditions like Cushing's syndrome. Similarly, increased appetite and hyperactivity do not relate to Addison's disease; rather, they may be associated with hyperthyroid states or other metabolic conditions. Excessive thirst and urination are typically linked to diabetes insipidus