Overview
A boil is a red, painful, pus-filled lump that forms when a hair follicle or oil gland gets infected, usually by staph bacteria. It starts as a firm tender bump and slowly softens as pus collects. Most small boils burst and heal on their own with warm compresses; larger ones or clusters may need a doctor to drain them and prescribe antibiotics.
Symptoms
- A red, tender lump that grows over a few days
- A white or yellow pus point at the centre
- Warmth and swelling of the surrounding skin
- Pain that eases once the boil drains
- Sometimes fever if the infection spreads
When to see a doctor
See a doctor if a boil is very large or painful, keeps coming back, appears on the face or spine, or comes with fever.
Causes
Bacteria entering through tiny breaks in the skin. Friction, sweating, poor hygiene, diabetes and a weak immune system make boils more likely.