Hong Kong Pacific Diabetes & Endocrine Centre
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endocrine diseases

Hong Kong Pacific Diabetes
& Endocrine Centre

Adrenal Gland

Adrenal gland is an endocrine gland sitting on top of both kidneys. Adrenal gland is responsible for releasing stress hormones such as cortisol and catechalamine. It also produces an important hormone aldosterone which regulates the body fluid balance and osmolarity.

Adrenal tumor can be functioning or nonfunctioning. There are three main functioning adrenal tumors: Conn’s adenoma, pheochromocytoma and Cushing’s syndrome. These three tumors are important causes of secondary hypertension, and they account for 1-2% of all hypertension. The age of onset is usually below age 50.

Conn’s adenoma is characterised by overproduction of mineralcorticoid hormone (aldosterone) by the adrenal glands. Excessive aldosterone causes renal sodium retention and potassium loss. This results in expansion of body sodium content and hypertension. Patient will also have hypokalaemia (low potassium level) and may present with tetany, myopathy and palpitation.

Pheochromocytoma is a catecholamine-secreting tumor arising from adrenal medulla. Though rare, it is an important cause of hypertension as it can be fatal if undiagnosed. Pheochromocytoma can present as episodic hypertension, headache, nausea, sweating, chest pain, anxiety, abdominal pain or high blood glucose. Worsely, it can be complicated with heart attack, stroke, arrhythmia, hypotension and even sudden death.

Cushings syndrome results from chronic excess cortisol secretion. Cortisol is a stress hormone, it has also other primary function of increasing blood sugar through gluconeogenesis, aiding in fat, protein, and carbohydrate metabolism and suppressing the immune system. Patient suffering from cushing’s syndrome presents as moonface, marked weight gain, hirsutism, menstrual irregularity, hypertension, high blood glucose, myopathy and osteoporosis. Patient may have mental disorder as well.