What are the causes for Boils?

Boils are usually caused by a bacteria called Staphylococcus (staph). Most staph infections develop into abscesses and can become serious very quickly. This germ can be present on normal skin and enters the body through tiny breaks in the skin or by traveling down a hair to the follicle. Certain health problems make people more susceptible to skin infections such as boils. Examples are
  • diabetes,
  • problems with the immune system,
  • poor nutrition,
  • poor hygiene, and
  • exposure to harsh chemicals that irritate the skin.

Source: http://www.emedicinehealth.com