Adrenal glands are situated over the top of each kidney. Adrenal adenomas are non-cancerous tumors of the adrenal gland. They arise from the outer layer of the gland, called the adrenal cortex. The adrenal cortex normally makes hormones that belong to the steroid family. If an adrenal adenoma produces hormones, it is called 'functioning', though this term makes them sound healthy when in fact such adenomas often produce excessive amounts of steroid hormones. If an adenoma does not produce a hormone it is termed 'non-functioning'.

Adrenal adenomas are often found by chance during a scan of the body for an unrelated condition. However, all adrenal masses (lumps) need careful evaluation to ascertain their nature, especially to see whether they are producing hormones. If an adrenal adenoma that is producing hormones is not treated, it can have serious consequences.

The cause of adrenal adenomas is unknown, but the current accepted theory is that they arise because of mutations (changes) in certain genes (which are not yet identified). Adrenal adenomas are more common in some inherited diseases, including multiple endocrine neoplasia type I, Beckwith-Wiedemann syndrome and the Carney complex. Also, patients with genetic defects of the body systems that manufacture steroid hormones (eg congenital adrenal hyperplasia), especially those whose condition is poorly controlled, may have a higher risk of adrenal adenomas. However, most adrenal adenomas are not related with an inherited disease. The likelihood of developing an adenoma increases with age.
About 6 per cent of patients over 60 years of age have an adrenal adenoma.

Most patients with an adrenal adenoma will have no symptoms caused by the adenoma. However, even in symptom-free patients, proper investigations reveal that many adrenal adenomas produce abnormal amounts of steroid hormones to some degree. The commonest abnormality is the production of too much cortisol, a steroid hormone involved in the response to stress and energy balance. Adenomas that produce massive amounts of steroid hormones will cause obvious symptoms. Large amounts of cortisol will cause Cushing's syndrome, too much aldosterone causes Conn's syndrome, and an excess of male sex steroids causes acne and hair growth. Very rarely, bleeding can occur into adenomas and cause pain in the flanks or back.

Most adrenal adenomas are discovered by chance when an abdominal computed-tomography (CT) or magnetic-resonance imaging (MRI) scan is done for unrelated symptoms.

More rarely, a mass in the adrenal gland is cancer that has spread from another part of the body, usually the lung or bowel (ie 'metastasis' cancer). Generally, the origin of the cancer is clear from the clinical examination or from simple tests such as a chest X-ray. In addition, the CT or MRI appearance of metastasis cancer in the adrenal gland can be distinguished from a benign adrenal adenoma by use of specialized radiology. An adrenal mass might also be a cancer of the adrenal cortex (adrenocortical carcinoma). Although they are very rare, these cancers are often large and can produce a combination of hormones.

Adrenal masses can also arise from the inner part of the adrenal gland, called the adrenal medulla, which is part of the nervous system and produces the hormones adrenaline and noradrenaline. Tumors of the adrenal medulla are called phaeochromocytomas, and they also can be distinguished from adenomas by specialized scanning techniques as well as by blood and urine tests for adrenaline and noradrenaline.

Adrenal glands are two small but very important glands, situated one above each kidney, which produce a range of hormones, or 'chemical messengers'. Under activity of the adrenal glands is called hypoadrenalism.

Many of the symptoms of hypoadrenalism are due to a deficiency of the steroid hormone cortisol, which is a potentially fatal deficiency if left uncorrected. These is call the Kidney's Yin deficiency. Each adrenal gland consists of two parts:
an outer ring - the cortex
an inner core - the medulla.
The two parts have separate hormone functions and control mechanisms. The production of cortisol in the cortex is controlled by the hormone adrenocorticotropin (ACTH), which is produced by the pituitary gland at the base of the brain which is also call the associated Kidney's Qi.

The way in which the pituitary gland regulates the normal production of steroid hormones by the adrenal gland is through the secretion of ACTH. If the adrenal gland produces too little cortisol, then there will be a lower level of cortisol in the blood. This is sensed by the pituitary, which therefore will increase the release of ACTH, which in turn stimulates the adrenal cortex to produce more cortisol.

Conversely, too much circulating steroid hormone will switch off the release of ACTH from the pituitary gland, which in turn reduces the adrenal gland production of steroids.

Primary hypoadrenalism or Addison's disease, results from failure of the adrenal glands themselves. This is usually an 'autoimmune' disease, where the immune system produces antibodies that attack tissues of the body rather than a virus or bacteria. In Addison's disease, antibodies attack the adrenal cortex, causing damage and scarring. Antibodies to the adrenal cortex can be detected in the blood of some patients. This is also call the Kidney's Qi .

Secondary hypoadrenalism or ACTH deficiency
Secondary hypoadrenalism, or ACTH deficiency hypoadrenalism, is caused by diseases of the pituitary gland, which lead to adrenal failure as a secondary effect.

Other causes Tuberculosis of the adrenal glands may also cause hypoadrenalism. This was a common cause of Addison's disease in Britain before the 20th century and remains a major cause in underdeveloped countries. Tuberculosis destroys the whole gland, both the cortex and the medulla. There are usually signs of tuberculosis in other organs, particularly the lungs. Destruction of the adrenal glands by tuberculosis is irreversible once hormonal deficiencies are clinically detectable. Being the Lung's which is the Metal and the Kidney the Water, Metal give rise to Water, Lung give rise to Kidney, the Five Elements.