You get a stye when bacteria, usually staphylococcus, infect one of the small oil glands at the base of your eyelashes. The infection causes a red, painful bump on the eyelid that looks similar to a pimple. Styes are one of the most common eyelid problems, and understanding what triggers them can help you avoid repeat episodes.
What Causes a Stye
Your eyelids contain dozens of tiny oil glands that help lubricate the surface of your eye. When one of these glands gets clogged with dead skin cells, old oil, or debris, bacteria that normally live on your skin can multiply inside the blocked gland and trigger an infection. That infection is a stye.
There are two types. An external stye forms at the edge of your eyelid, right at the root of an eyelash, and is the more common variety. An internal stye develops deeper in the lid, inside one of the larger oil-producing glands (called meibomian glands) that line the inner surface of the eyelid. Internal styes tend to be more painful and take longer to clear up.
Everyday Habits That Raise Your Risk
The most direct way to introduce bacteria to your eyelids is by touching your eyes with unwashed hands. Rubbing your eyes after touching doorknobs, phones, or gym equipment transfers staphylococcus bacteria right where they can do damage. This is the single most common trigger.
Eye makeup is another major contributor. Mascara, liquid eyeliner, and eyeshadow sit right along the lash line, and over time bacteria build up inside the product. Mascara and liquid eyeliner should be replaced every six months. Liquid eyeshadow lasts six months to a year, while powder eyeshadow and pencil eyeliners can go one to two years. Wet products spoil faster because the moisture encourages bacterial and mold growth. Sharing eye makeup with others is essentially sharing bacteria, and sleeping in your makeup gives bacteria hours of uninterrupted contact with your oil glands.
Contact lens hygiene matters too. Putting in or removing lenses with dirty hands, reusing old solution, or wearing lenses longer than recommended all increase the chance of introducing bacteria to your eyelids.
Medical Conditions That Make Styes More Likely
Some people get styes repeatedly, and that often points to an underlying eyelid condition. Blepharitis, a chronic inflammation of the eyelid margins, creates a persistently irritated environment where oil glands clog more easily. People with blepharitis often notice crusty flakes along their lash line, especially in the morning.
Meibomian gland dysfunction is another common culprit. In this condition, the oil glands in your eyelids either don’t produce enough oil or produce oil that’s too thick to flow properly. The glands fill up, the oil can’t get out, and the resulting blockage sets the stage for infection. Untreated meibomian gland dysfunction can cause chronic, recurring styes. Ocular rosacea, a form of rosacea that affects the eyes, also increases eyelid inflammation and gland blockage.
How a Stye Feels
A stye is typically very painful. It starts as a tender, swollen spot on the eyelid and develops into a visible red bump, often with a small white or yellow head where pus has collected. Your eye may water more than usual, and the eyelid can feel heavy or swollen enough to partially obstruct your vision. You might also notice sensitivity to light.
A stye is sometimes confused with a chalazion, but they feel quite different. A stye appears at the eyelid’s edge and hurts. A chalazion develops farther back on the lid, is not usually painful, and tends to grow more slowly. That said, a stye that doesn’t drain can harden into a chalazion over time.
Are Styes Contagious?
A stye is generally not contagious in the way a cold or flu is. You won’t give someone a stye by being in the same room. However, it is possible to spread small amounts of bacteria from a stye through direct contact. That’s why washing your hands before and after touching your face matters while you have one. Washing your pillowcases frequently during an active stye also helps prevent the bacteria from spreading to your other eye or to someone who shares your bed.
How Long Styes Last
Most styes resolve on their own within a few days to a couple of weeks. The standard home treatment is a warm compress: a clean washcloth soaked in warm water, held against your closed eyelid for about 10 minutes at a time, several times a day. The heat helps liquefy the trapped oil and encourages the gland to drain naturally. After the compress, gently cleaning your eyelid and lashes with your eyes closed for about 30 seconds removes loosened debris.
One important rule: never squeeze or pop a stye. Forcing it open can spread the infection deeper into the eyelid tissue. If a stye hasn’t improved after two weeks, grows rapidly, affects your vision, or causes the entire eyelid or surrounding skin to become red and swollen, that’s a sign the infection may need professional treatment.
Preventing Styes From Coming Back
If you’ve had one stye, you’re more likely to get another, especially if the underlying cause (a clogged or dysfunctional oil gland) hasn’t been addressed. A few daily habits make a real difference:
- Keep your hands away from your eyes. If you need to touch your eyelids, wash your hands first with soap and water.
- Clean your eyelids regularly. A daily warm compress for 10 minutes followed by gentle lid cleaning helps keep oil glands open and flowing, particularly if you have blepharitis or meibomian gland dysfunction.
- Replace eye makeup on schedule. Toss mascara and liquid liner at the six-month mark regardless of how much is left. If you develop any eye infection, throw out all your current eye products and start fresh.
- Remove makeup before bed. Sleeping in eye makeup is one of the easiest ways to clog the glands along your lash line.
- Handle contact lenses properly. Always wash and dry your hands before inserting or removing lenses, and follow your prescribed replacement schedule.
For people with chronic styes tied to meibomian gland dysfunction, in-office treatments exist that use controlled heat and gentle pressure to clear blocked glands more thoroughly than a warm washcloth can. These procedures can reduce stye frequency significantly when home care alone isn’t enough.