Diseases and Conditions
Boils and carbuncles
Boils
Overview
Symptoms
Causes
Risk factors
Complications
Prevention
Diagnosis
Treatment
Lifestyle and home remedies
Preparing for an appointment
Causes
Most boils are caused by Staphylococcus aureus, a type of bacterium commonly found on the skin and inside the nose. A bump forms as pus collects under the skin. Boils sometimes develop at sites where the skin has been broken by a small injury or an insect bite, which gives the bacteria easy entry.