How Do You Get Styes on Your Eyelid: Causes & Risks

Styes develop when bacteria infect an oil gland or hair follicle along the edge of your eyelid, and the bacterium most often responsible is Staphylococcus aureus, a common skin-dwelling microbe that causes trouble when it gets trapped inside a blocked gland.¹ The blockage itself can be triggered by anything from chronic eyelid inflammation to tiny parasitic mites, and certain skin conditions and everyday habits raise the odds considerably.

What Actually Happens Inside Your Eyelid

Your eyelids are lined with small oil-producing glands. The largest group, the meibomian glands, sit deep in the eyelid and secrete an oily layer that keeps your tear film from evaporating too quickly. Closer to the surface, two smaller types of glands sit right at the base of your eyelashes. All of these glands have narrow openings that can become clogged with dead skin cells, hardened oil, or debris. When a clog traps bacteria inside, the gland swells, fills with pus, and forms the red, painful lump you recognize as a stye.

The medical name for a stye is a hordeolum. If the infection hits a gland near the lash line, it is called an external hordeolum, which looks like a pimple right at the eyelid margin. If it strikes a meibomian gland deeper in the lid, it is an internal hordeolum, which tends to be more painful and may not be visible from the outside at first. Both types start the same way: bacteria colonize a blocked gland and trigger an acute, pus-forming infection.

Why Staphylococcus Aureus Is Almost Always Involved

S. aureus naturally colonizes your skin, nostrils, and eyelid margins without causing harm most of the time. It becomes a problem when it gains access to a sealed space, like a plugged oil gland, where it can multiply quickly. Once inside, the bacteria release enzymes and toxins that damage surrounding tissue, and your immune system responds with inflammation, swelling, and pus formation.¹ S. aureus is capable of infecting nearly every structure of the eye, from the tear duct to the interior chambers, but styes represent one of its most superficial and common effects. The bacterium is also easily transferred between people through shared towels, pillowcases, or contaminated hands, which is one reason styes sometimes seem to pop up in clusters within a household.

Blepharitis and Chronic Eyelid Inflammation

If you get styes repeatedly, the most likely underlying cause is blepharitis, a chronic, low-grade inflammation of the eyelid margins. Blepharitis disrupts the normal flow of oil from the meibomian glands, thickens the secretions, and creates an environment where bacteria thrive. The condition often appears as crusty debris along the lash line, redness, and a gritty sensation in the eyes. Because blepharitis and styes share the same root problem, blocked and infected glands, medical literature often describes them as part of a continuum rather than entirely separate diseases.²

Meibomian gland dysfunction, where the glands produce abnormally thick or insufficient oil, is one of the most common conditions eye doctors see in clinic and a leading driver of evaporative dry eye.³ It creates a self-reinforcing cycle: sluggish glands are more prone to blockage, blockages encourage bacterial overgrowth, and the resulting inflammation further impairs gland function. Traditional management centers on warm compresses to soften hardened oil, lid hygiene to clear debris, and sometimes topical antibiotics or anti-inflammatory agents to break the cycle.³

Demodex Mites and Recurrent Styes

Tiny parasitic mites called Demodex live in the hair follicles and oil glands of most adults, usually without causing symptoms. Two species are relevant to your eyelids: Demodex folliculorum, which inhabits eyelash follicles, and Demodex brevis, which burrows into meibomian glands and the smaller glands along the lash line.⁴ When mite populations grow large enough, they cause real damage. Their sharp mouthparts create micro-abrasions in the follicle lining, triggering inflammation and hyperkeratinization, a thickening of the tissue that further clogs the gland openings.⁵

The mites also deposit waste products containing digestive enzymes, keratin fragments, and eggs directly onto your eyelid tissue. These deposits can trigger allergic-type inflammatory responses and surface irritation.⁵ A hallmark sign of Demodex-related eyelid disease is cylindrical dandruff, a waxy, collarette-shaped crust that wraps around the base of each lash. Studies of patients with posterior blepharitis find a high prevalence of Demodex infestation, with the mite burden increasing with age.⁶ Among the clinical consequences researchers have linked to Demodex infestation are recurrent styes and chalazia, dry eye, foreign-body sensation, and decreased visual acuity.⁴

If you keep getting styes despite good hygiene, Demodex is worth investigating. An eye doctor can often spot cylindrical dandruff during a routine slit-lamp exam, and targeted treatments, including tea tree oil-based lid scrubs and newer prescription options, can reduce mite populations.

Rosacea and Your Eyes

Rosacea is best known for causing facial redness and flushing, but it frequently affects the eyes in ways that surprise people. Ocular rosacea involves chronic inflammation of the eyelids and the surface of the eye, and its clinical features include meibomian gland disease, blepharitis, and conjunctivitis.⁷ Chalazia and styes are described as frequent indicators of the condition.⁸

The connection makes biological sense: rosacea drives chronic inflammation in the blood vessels and glands of the face, including the eyelids. That inflammation thickens meibomian gland secretions and destabilizes the tear film, setting up the same blockage-then-infection pattern behind most styes. Eye symptoms sometimes appear before any skin symptoms, so a person who gets styes frequently and also tends toward facial flushing or redness should mention both to their doctor. Treating the underlying rosacea, often with low-dose oral antibiotics that also have anti-inflammatory effects, can reduce the frequency of eyelid flare-ups.

Does Diabetes Raise Your Risk?

This is one area where the evidence is genuinely mixed. People with diabetes are broadly more susceptible to bacterial infections because elevated blood sugar can impair immune cell function. One study of patients with type 2 diabetes found eyelid lesions in a notable number of participants, with hordeolum (styes) among the most common findings.⁹ However, a larger cohort study that specifically tested whether diabetes and blood sugar control were linked to various eye infections found no association between diabetes and styes or chalazia in the general population, and glycemic control did not change the picture.¹⁰

What does this mean practically? Diabetes may contribute to stye formation in individual patients, especially those with poorly controlled blood sugar and concurrent blepharitis, but it does not appear to be a strong independent risk factor on its own. If you have diabetes and experience frequent styes, it is probably worth addressing eyelid hygiene and meibomian gland health directly rather than assuming blood sugar is the sole driver.

Contact Lenses and Everyday Habits

Anything that introduces bacteria to your eyelids or disrupts the normal oil flow raises your risk. Contact lenses are a particularly efficient vehicle for both. A survey of contact lens users found widespread hygiene lapses: nearly half exceeded the recommended replacement schedule, about a third slept in their lenses, and only a small fraction cleaned their lenses daily.¹¹ Roughly a third of users in that study reported at least one lens-related complication, including red eye and conjunctivitis. While the study focused on surface infections rather than styes specifically, the mechanism is straightforward: a lens that sits on your eye for too long traps bacteria against the lid margin and disrupts the tear film that normally flushes debris away.

Beyond contact lenses, a few everyday behaviors matter:

Touching your eyes: Your hands carry S. aureus from surfaces, doorknobs, and your own nose. Rubbing your eyes transfers bacteria directly to the eyelid margin.
Old or shared cosmetics: Mascara and eyeliner wands collect bacteria over time. Sharing eye makeup is essentially sharing a bacterial inoculum. Replacing mascara every few months and never sharing applicators reduces exposure.
Sleeping in makeup: Cosmetics left on overnight mix with skin oils and dead cells, forming a paste that clogs gland openings.
Incomplete face washing: Leaving residue along the lash line, whether from soap, sunscreen, or makeup remover, gives bacteria a foothold.

None of these habits guarantee you will develop a stye, but each one shifts the odds by creating the conditions bacteria need: a warm, blocked gland with a fresh supply of nutrients.

Air Pollution and Gland Health

Environmental factors are an underappreciated piece of the puzzle. A study comparing populations living near different industrial sources found that people in areas with higher ozone and sulfur dioxide concentrations had more frequent and more severe signs of meibomian gland dysfunction, along with elevated inflammatory markers in their tear fluid.¹² Long-term exposure correlated with visible changes in the glands themselves, including increased blood vessel growth along the lid margin and greater gland tissue loss.

The practical takeaway is that people living in heavily polluted urban areas or near industrial facilities may have a higher baseline rate of gland clogging, even if their personal hygiene is excellent. If you live in a high-pollution environment and deal with recurring styes, simple protective steps like wearing wraparound sunglasses outdoors and using preservative-free lubricating eye drops can help buffer the effects.

When a Bump on Your Eyelid Is Not a Stye

Not every red lump on your eyelid is a stye, and knowing the difference matters because the treatments diverge. The most common look-alike is a chalazion, which forms when a meibomian gland becomes blocked and the trapped oil triggers a slow, chronic inflammatory reaction rather than an acute infection. Chalazia are firm, usually painless, and can persist for weeks or months. A stye, by contrast, is acutely painful, warm, and often comes to a visible white or yellow head within a few days. Clinically, the two conditions sit on a spectrum: a stye can sometimes evolve into a chalazion once the acute infection resolves but the blocked gland remains inflamed.²

A more serious concern is a chalazion or stye-like bump that keeps coming back in the same spot. Sebaceous gland carcinoma, a rare but aggressive eyelid cancer, can masquerade as a recurring chalazion. One case report describes a 52-year-old woman whose recurrent chalazion ultimately turned out to be sebaceous gland carcinoma. The authors note that a majority of premalignant and malignant eyelid lesions that are initially misdiagnosed as chalazia present as primary cases, meaning there was no prior cancer diagnosis to raise suspicion.¹³ The message here is not to panic about every stye but to take recurrence in the same location seriously, especially if you are over 50. A biopsy of any persistent or repeatedly recurring eyelid lump is a reasonable precaution.

Omega-3 Fatty Acids and Meibomian Gland Function

Because so many styes trace back to thickened, sluggish meibomian gland secretions, researchers have explored whether dietary changes can improve the quality of the oil those glands produce. A pilot study of omega-3 supplementation found that after twelve months, patients in the omega-3 group showed improvement in tear film stability, symptom scores, and the quality of meibomian gland secretions. The level of saturated fatty acids in their meibum, the waxy oil the glands produce, decreased, suggesting a shift toward a more fluid secretion that is less likely to clog gland openings.¹⁴

This is a single small study, so it is not enough to make dietary omega-3s a definitive recommendation for stye prevention. But the biological logic is sound: if the oil your glands produce is thinner and flows more freely, blockages become less likely, and fewer blockages mean fewer opportunities for bacteria to set up an infection. Foods rich in omega-3s, like fatty fish, flaxseed, and walnuts, are already recommended for general health, so incorporating them is a low-risk intervention worth trying if you are prone to eyelid problems.

Why Some People Get Styes Repeatedly While Others Never Do

The frustrating reality is that stye susceptibility varies enormously between people, even when outward hygiene habits look identical. Several factors converge to explain this. Some people naturally produce thicker meibomian gland oil that is inherently more prone to solidifying and blocking the gland opening. Others carry heavier-than-average S. aureus colonization on their skin, meaning there is always a larger bacterial population ready to exploit any blockage. The Demodex mite burden mentioned earlier increases with age and varies between individuals, adding another variable.⁶

Underlying skin conditions like rosacea and seborrheic dermatitis create a chronically inflamed eyelid environment that primes the glands for trouble.⁸ Hormonal shifts, particularly during puberty and menopause, alter sebum production and can trigger flare-ups. Stress and sleep deprivation, while not studied specifically in the context of styes, are well-established modulators of immune function and skin inflammation, and many people report styes coinciding with periods of high stress.

If you find yourself getting more than two or three styes a year, treating each bump individually with warm compresses is treating the symptom rather than the cause. A more productive approach is to work with an eye doctor to identify which underlying factor, whether it is blepharitis, Demodex, rosacea, or gland dysfunction, is driving the cycle and address that directly. Daily lid hygiene with a gentle cleanser, consistent warm compresses to keep oil flowing, and treatment of any underlying condition can dramatically reduce recurrence over time.

1
PubMed Central. The Pathogenesis of Staphylococcus aureus Eye Infections
2
Survey of Ophthalmology. The lowly chalazion
3
PubMed Central. Emerging treatment options for meibomian gland dysfunction
4
Dermatology Review. Ophthalmic manifestations of Demodex spp. infection – what should a dermatologist know?
5
PubMed Central. Demodex Blepharitis: A Comprehensive Review of the Disease, Current Management, and Emerging Therapies – Section: MECHANISMS OF DISEASE
6
PubMed. High prevalence of Demodex spp. infestation among patients with posterior blepharitis: correlation with age and cylindrical dandruff
7
JEADV Clinical Practice. Ocular rosacea: The often‐overlooked component of rosacea
8
PubMed Central. Ocular Rosacea: An Updated Review – Section: CLINICAL FEATURES AND DIFFERENTIAL DIAGNOSIS
9
European Journal of Cardiovascular Medicine. Association of Ocular Manifestation with Glycemic Control in Patients with Type 2 Diabetes Mellitus
10
PubMed. The association between diabetes, level of glycaemic control and eye infection: Cohort database study
11
PubMed Central. Prevalence, habits and outcomes of using contact lenses among medical students
12
PubMed Central. The effects of short-term and long-term air pollution exposure on meibomian gland dysfunction
13
PubMed Central. Sebaceous Gland Carcinoma of Lid: Masquerading as a Recurring Chalazion
14
PubMed Central. The role of omega-3 dietary supplementation in blepharitis and meibomian gland dysfunction (an AOS thesis)