Chaffing of the underarms is usually a problem that is caused due to the pressure of two folds of skin. It can also be caused by too much hair in the underarms combined with the above problem that results in the rubbing off of your underarm skin. Ideally, the best way to solve this problem is to simply remove the hair from your underarms and lose some weight but this can take some time - especially, losing weight. Therefore, a better alternative might be to change your wardrobe slightly and avoid wearing tight clothes, so that the two folds of your skin don't meet.
The skin of the underarms is very sensitive because it is usually not subject to a lot of pressures like the other skin is subject to. However, at the same time, this piece of skin is also stretched, pulled, and injured from hair removal techniques more than any other part of the body. Another problem that makes underarm injury an issue is that it is a closed and moist space making it a perfect breeding ground for infectious bacteria. Bacteria live all over the human body and are a natural occurrence but the underarms, offer a perfect, warm, moist environment for them to grow. Most skin bacteria are quite harmless but nearly all of them are opportunistic. This means that they are benign as long as they are just feeding off the waste products of the skin but the moment these bacteria enter into the skin through a wound, they immediately move into an infectious mode. This can end up requiring topical antibiotic ointments and other treatments to solve it. However if the condition is left alone, it would most probably result in a boil. The wounds that can occur are usually caused by chaffing of the skin and from a shaving injury.
The first step to losing some weight is to start eating right. The fastest way to losing weight is to move to a strictly salad based diet for a week and the results will start to show immediately as your body starts to use up its reserves of fat from the adipose tissue. Your underarm hair would also be a problem if you don't shave it off regularly. The stubble from previous shaves could also be an issue here. When you do shave, ensure that you shave with and against the grain to ensure that there are no remnants of hair at all. In time, chaffing won't be felt because your skin will start to harden and this will avoid further skin damage.
answered by G M