What is a sty?
A sty (sometimes spelled “stye”) is a red, painful bump that forms either on or inside the eyelid near the edge of the eyelashes. A sty that appears on the outside of the upper or lower eyelid, the more usual location, is called an external sty. A sty that appears on the inside of the upper or lower eyelid is called an internal sty. A sty can look like an acne pimple.
The medical term for a sty is a hordeolum.
A sty is similar to another bump that occurs in the eyelid called a chalazion. A chalazion is a bump that usually occurs farther back on the eyelid. Unlike a sty, a chalazion is usually not painful and is not caused by a bacterial infection. Instead, a chalazion occurs when the opening of the oil-producing glands in the eyelid becomes clogged. Treatment for both conditions, however, is similar.
Symptoms and Causes
What causes a sty?
A sty is caused by a bacterial infection in the oil-producing glands in the eyelid. Oil-producing glands line the eyelids and help lubricate the surface of the eye.
What are the signs and symptoms of a sty?
Signs and symptoms of a sty include:
- Painful red bump along the edge of the upper or lower eyelid near the base of the eyelashes
- Swelling of the eyelid (sometimes the entire eyelid)
- Crusting along the eyelid
- Sensitivity to bright light
- Sore, scratchy eye
- Tearing of the eye
- A feeling that there is something in the eye
Diagnosis and Tests
How is a sty diagnosed?
A sty is usually diagnosed by a visual exam of the eyelid.
What are the risk factors for developing a sty?
Styes are very common. Anyone can get a sty. However, you may be more likely to get a sty if you:
- Have had a sty before
- Have blepharitis (an inflammation of the eyelids)
- Have certain skin conditions, such as acne rosacea or seborrheic dermatitits
- Have diabetes
- Have dry skin
- Are experiencing hormonal changes
- Have high lipid levels (“bad” cholesterol)
Management and Treatment
What are the treatments for a sty?
A sty usually will disappear on its own in a few days. However, to reduce the pain and swelling, a sty can be treated at home with self care. Treat as follows:
- Apply a warm washcloth to the eyelid. Apply for 10 to 15 minutes at a time, 3 to 5 times a day. Rewarm washcloth as needed by soaking it in warm water. Wring out excess water, then reapply to the eyelid.
- Gently wipe away eyelid drainage with mild soap such as Johnson’s baby shampoo and water, or eyelid wipes (available in drug stores).
Also follow these tips:
- Do not squeeze or pop a sty.
- Do not rub or touch your eyelid.
- Do not wear makeup or contact lenses until the area has fully healed.
A sty that does not improve within 48 hours of self care may require medical treatment by a doctor. Treatments given by doctors include:
- In-office incision (under local anesthesia) to drain the sty
- Antibiotic ointment to apply to the eyelid or antibiotic eye drops. Sometimes antibiotic pills are prescribed if there is infection of the area surrounding the eye or after incision and drainage of an internal sty.
- Steroid injection into the sty to reduce the swelling in the eyelid
Can styes be prevented?
The best way to prevent a sty is by practicing good hygiene around your face and eyes, including:
- Wash your hands thoroughly and often and especially before touching your face and eyes.
- Wash your hands before and after removing contact lenses. Clean contacts with disinfectant and lens cleaning solution. Discard daily wear or other “limited use” lenses on the schedule recommended by your eye doctor.
- Wash your face to remove dirt and/or makeup before going to bed.
- Throw away all old or expired makeup. Replace mascara and eye shadow every 2 to 3 months. Never share or use another person’s makeup.
When should I see my eye doctor about a sty?
See your eye doctor if:
- Your eye is swollen shut due to the swelling in the eyelid
- Pus or blood is leaking from the bump
- Pain and/or swelling increases after the first 2 to 3 days
- Blisters have formed on your eyelid
- Your eyelid feels hot
- Your vision has changed
- Styes keep recurring. If this happens, a biopsy (a small piece of the sty) may need to be taken to rule out other more serious problems.