Dark underarms could possibly be caused because of dead skin in the underarms, an optical illusion that is caused by the remaining hair, and acanthosis nigricanis – a symptom of type 2 diabetes and obesity. The first two possibilities are treatable by performing skin exfoliation and shaving but acanthosis nigricanis is an indication that you need to get your blood sugar levels checked.
Exfoliation is the process of removing dead skin. One of the components of skin is a fibrous protein called collagen. As skin gets older, it dies as it reaches the surface. It usually falls off the skin in microscopic quantities from frictional forces and being rubbed off. Dead skin removal can be sped up to reveal new skin below by using some salicylic acid or freshly squeezed lemon juice. Apply it on the area required and then, using an abrasive like salt or sugar, rub the area in a circular motion. This should be followed up with skin bleach by applying some onion juice on the underarm. To eliminate the possibility that the darkening is caused by stubble-like hair inside the skin, change the type of blade you are currently using to shave to a more powerful, triple blade razor. This will cut much deeper into the skin and leave less visible shadows. It is important to understand that it is not the skin itself that is dark. It is rather an optical illusion that is caused by the thick hairs from within the skin showing the appearance of a dark patch.
Yet another possibility, with serious undertones that is causing underarm darkening is type 2 diabetes. Diabetes is a condition in which there is too much blood sugar in your system. The excess sugar eventually ends up being excreted in the urine. The primary cause of type 1 diabetes is insulin production being stopped in the pancreas or by resistance to insulin resistance in the body – as is the case in type 2 diabetes. Type 2 diabetes is more serious as it will progressively kill since the body is impervious to the effects of insulin – the sugar regulation hormone and fuel switch. Type 2 diabetes has a visible symptom in acanthosis nigricanis – a condition of hyperpigmentation. The mechanism of action is that when insulin is flowing freely in the blood in high quantities, the insulin sometimes ends up in the pigment creating cells of our body, called melanocytes. Insulin then causes these cells to create a lot of melanin – the skin pigment, and on exposure to the sun, the melanin darkens. Typically, the areas that are affected with hyperpigmentation are the back of the neck, armpits and groin.