What does a boil look like and what causes a boil? A boil is a localized infection deep in the skin that can be caused by anything from sweat and dirt to an ingrown hair, splinter or cut. A boil generally starts as a tender area, is red in color and painful to touch. A boil is also referred to as a skin abscess.
After a few days, the boil will become bigger, softer and quite sore. This is because pus has formed inside the boil. The pus is full of bacteria and white blood cells that are trying to fight the infection.
Pictures of boils. There are many causes of boils. Some boils can be caused by an ingrown hair, a splinter or other foreign material that has become lodged in the skin. Others boils, such as those of acne, are caused by plugged sweat glands that become infected.
The skin is an important part of our immune defense against materials and microbes that are foreign to our body. Any break in the skin, such as a cut or scrape, can develop into a skin abscess should it become infected with bacteria.