Addison's disease, also known as primary adrenal insufficiency disorder, is a rare adrenal gland disease. Its worldwide incidence is only 6 out of 1 million, primarily affecting females in their 30s to 50s.
Adrenal glands are two small, triangular glands located above the kidneys. Like other glands, they produce hormones, particularly cortisol and aldosterone. Addison's disease affects the cortex (the outer layer) of the adrenal glands, stopping the normal production of these hormones. As a result, the patient's body encounters deficiency of the adrenal hormones, followed by a series of physiological reactions.
There are 2 types of adrenal insufficiency: primary and secondary. The difference is in their disease processes and hormones affected.
Primary adrenal insufficiency (Addison's disease). It is caused by the direct destruction of the adrenal glands. The most common aetiology is autoimmune diseases, meaning the body's immune cells attack their own's body tissue.
Secondary adrenal insufficiency. It may happen in people taking an extended period of steroids. Cortisol itself is a steroid hormone that is naturally produced by the adrenal glands. When there are external steroids that are like cortisol, the body reacts by the pituitary gland (the major command centre for hormones, which lie just beneath our brain) reducing production of ACTH – the hormone that will act on the adrenal gland to command it to produce cortisol. As such, if ACTH is suppressed, the adrenal glands go to sleep and stop producing cortisol.
People with Addison's disease may present with fatigue, body weakness, weight loss, nausea, vomiting, abdominal pain, dizziness, fast heart rate, low blood pressure and irregular periods in females.
Another distinct feature of Addison's disease is hyperpigmentation (dark spots), commonly at the palmar creases, nail beds, knuckles, gum, edge of lips, elbows, back of neck, and area around the nipples.
Symptoms of Addison's disease are often non-specific and progress silently, making them difficult to be identified.
Therefore, many people are unaware that they have Addison's disease until the hormone levels are low enough to cause severe symptoms. This condition is called an adrenal crisis, a potentially lethal emergency that requires immediate medical attention.
Any conditions that damage the adrenal gland can cause Addison's disease. They can be classified into several groups as below:
The risk of Addison's disease increases when one has these coincident autoimmune diseases:
Addison's disease can turn into an adrenal crisis, which is an acute, severe life-threatening event. Adrenal crisis may present with :
In long-term Addison's disease, depleted hormones can impact all body systems, causing significant complications as below:
Prevention is of utmost importance, considering the lethal complications of adrenal crisis. Here are some tips: