Signs and symptoms of a sty include:
- A red lump on your eyelid that is similar to a boil or a pimple
- Eyelid pain
- Eyelid swelling
- Crusting around the eyelids
Another condition that causes inflammation of the eyelid is a chalazion. A chalazion occurs when there's a blockage in one of the small oil glands at the margin of the eyelid, just behind the eyelashes. The gland can become infected with bacteria, which may also cause a red, swollen eyelid. Unlike a sty, a chalazion tends to be most prominent on the inner side of the eyelid. Treatment for both conditions is similar.
When to see a doctor
Most sties are harmless to your eye and won't affect your ability to see clearly. Try self-care measures first, such as applying a warm washcloth to your closed eyelid for 10 to 15 minutes several times a day. Contact your doctor if:
- The sty doesn't start to improve after 48 hours
- Redness and swelling extend beyond your eyelid and involve your cheek or other parts of your face
You risk exposing your eyelids to infection if you:
- Change your contact lenses without thoroughly washing your hands first
- Fail to disinfect your contact lenses before putting them in
- Leave eye makeup on overnight
- Use old or expired cosmetics
To prevent eye infections:
- Wash your hands. Wash your hands with soap and warm water or use an alcohol-based hand sanitizer several times each day. Keep your hands away from your eyes.
- Take care with cosmetics. Reduce your risk of recurrent eye infections by throwing away old cosmetics. Be sure to throw away any eye cosmetics you used when you had a sty. Don't share your cosmetics with others.
- Make sure your contact lenses are clean. If you wear contact lenses, wash your hands thoroughly before inserting your contacts and follow your doctor's advice on disinfecting your contacts.
- Manage blepharitis. If you have blepharitis, follow your doctor's instructions for caring for your eyes.