A stye forms when bacteria, almost always Staphylococcus aureus, infect one of the tiny oil or sweat glands along your eyelid margin. These glands can become blocked, and once secretions get trapped inside, bacteria that normally live on your skin multiply and cause a painful, red bump. The good news: most styes resolve on their own within one to two weeks without any medical treatment.
What’s Actually Happening in Your Eyelid
Your eyelids contain dozens of small glands that produce oil and sweat to keep your eyes lubricated. When one of these glands gets clogged, the trapped secretions create a breeding ground for staph bacteria. The result is a localized infection that swells into the tender bump you’re seeing.
There are two types. An external stye, the more common kind, develops at the base of an eyelash where it meets a small oil or sweat gland. It typically shows up as a yellowish pustule right at the eyelid’s edge. An internal stye forms deeper inside the eyelid, in one of the larger oil-producing glands (called meibomian glands) that line the inner surface. Internal styes tend to be more painful and can occasionally cause fever or chills because the infection sits in deeper tissue.
Common Reasons You Developed One
Several everyday habits make stye infections more likely:
- Touching or rubbing your eyes transfers bacteria from your hands directly to the vulnerable gland openings on your eyelid.
- Old eye makeup is a hidden culprit. Bacteria grow in mascara and eyeliner over time, so any product older than six months significantly raises your risk.
- Sleeping in makeup keeps pores and gland openings blocked for hours, giving bacteria time to settle in.
- Contact lens handling without proper hand washing introduces bacteria near the eye with every insertion and removal.
If none of these apply to you, the cause may simply be bad luck. Staph bacteria live on most people’s skin, and sometimes a gland clogs for no obvious reason.
Stress, Sleep, and Your Immune System
You may have heard that stress causes styes. There’s no direct clinical evidence for that, but there is a plausible chain of events. Stress hormones can weaken your immune response, making you more susceptible to infections of all kinds, including the bacterial infections behind styes. One 2017 study found that certain stress hormones may even help attract bacteria to vulnerable areas of the body.
Sleep deprivation works similarly. Poor sleep reduces the effectiveness of T cells, the immune cells responsible for fighting off infections. There’s also a practical side to being exhausted: when you’re tired, you’re more likely to skip removing makeup before bed or to rub your eyes without thinking. Both of those shortcuts create openings for bacteria.
Why Styes Keep Coming Back
If you’re getting styes repeatedly, a chronic eyelid condition may be the underlying issue. Meibomian gland dysfunction, where the oil glands in your eyelids don’t function properly, is the most common cause of recurrent styes. The glands become chronically blocked, creating a cycle of clogging and infection. Recurring styes and persistent blockages in your tear system are hallmark signs of this condition.
Rosacea, the skin condition that causes facial redness and flushing, is a known risk factor for meibomian gland dysfunction. If you have rosacea and keep getting styes, the two are likely connected. Chronic eyelid inflammation (blepharitis) also keeps the gland openings irritated and prone to blockage.
How a Stye Heals
Most external styes follow a predictable pattern. The bump appears and grows more tender over the first one to two days. Within two to four days, it usually comes to a head and ruptures on its own, releasing pus and relieving the pain. Total healing takes one to two weeks.
You can speed this up with warm compresses. Hold a clean, warm washcloth against your closed eyelid for two to five minutes at a time, as many as 20 times a day if you can manage it. The warmth helps loosen the blocked secretion and encourages the stye to drain. The water should be comfortably hot but not scalding. Don’t squeeze or pop a stye, as this can spread the infection into surrounding tissue.
If the pain and swelling haven’t started improving after 48 hours of warm compresses, or if they get noticeably worse after two to three days, it’s time to see an eye doctor. In some cases, a stye won’t drain on its own and needs to be opened by a professional.
When a Stye Becomes Something More Serious
Rarely, the infection can spread beyond the stye itself into the soft tissue surrounding the eye, a condition called periorbital cellulitis. If left untreated, this can progress further into the deeper eye socket. Watch for these warning signs: fever combined with pain, swelling that spreads across the entire eyelid or around the eye socket, any changes in your vision, or the eye beginning to bulge. These symptoms need immediate medical attention.
Preventing the Next One
The single most effective prevention strategy is keeping your eyelids clean. Wash your hands before touching your face or eyes. Replace mascara and eyeliner every six months, and never share eye makeup. Remove all eye makeup before bed, every night.
If you wear contact lenses, clean them according to their recommended schedule and always handle them with freshly washed hands. For people prone to recurrent styes, daily eyelid scrubs can make a real difference. You can use commercial lid scrub pads or gently clean along your lash line with a cotton swab dipped in diluted baby shampoo. This keeps the gland openings clear and reduces the bacterial load on your eyelid margins.