Each kidney contains about one million tiny units called nephrons. Each nephron is made up of a very small filter, called a glomerulus, which is attached to a tubule. As blood passes through the nephron, fluid and waste products are filtered out.
Early Warning: Folliculitis. Folliculitis is an inflammation or infection of the hair follicles that can develop into a boil. Tiny pimples with whiteheads appear around individual hairs, sometimes surrounded by red skin. It can be itchy, tender, and uncomfortable, but is typically not as painful or deep as a boil.
How long a boil lasts. Boils are often painful. The skin covering and around the bump is tender, making it susceptible to skin breakage that may lead to further skin infection. Boils often occur in body regions that are humid and may last for some days to weeks to fully heal, depending on how severe the infection is.