A stye is a tender red bump on the edge of your eyelid, caused by a bacterial infection in a gland or hair follicle. The hallmark symptom is localized pain and swelling that develops quickly, usually over a day or two. Most styes resolve on their own within one to two weeks, but knowing what to look for helps you tell a stye apart from other eyelid bumps and recognize when the infection needs attention.
Primary Symptoms
The most noticeable symptom is a painful, red bump right at the eyelid margin, often centered around the base of an eyelash. The area around it becomes swollen, and the skin may feel warm to the touch. As the infection progresses over a few days, you’ll typically see a yellowish-red spot form at the center of the bump where pus is collecting.
Beyond the bump itself, styes cause several other eye-related symptoms:
- Tearing and crusting: The affected eye often waters more than usual, and you may wake up with dried crust along the lash line.
- Foreign body sensation: It can feel like something is stuck in your eye, even though nothing is there.
- Light sensitivity: Bright light may bother the affected eye more than normal.
- Eyelid soreness: The entire eyelid can feel tender, not just the bump itself.
Most styes come to a head and release pus on their own after a few days. Once that happens, the pain usually drops off quickly and the swelling starts to go down.
External vs. Internal Styes
Not all styes look the same, and where the bump forms changes the experience. An external stye is the more common type. It develops at the root of an eyelash, where a small oil gland has become infected. You’ll see redness and swelling right around a specific lash, and the bump is clearly visible on the outer surface of your eyelid.
An internal stye forms deeper inside the eyelid, in one of the larger oil glands that line the inner surface. Instead of pointing outward, the bump points toward the inside of the lid. You may not see much on the outside at first, just feel a deep ache and notice general eyelid swelling. If you gently flip the eyelid, you can sometimes spot a yellowish area on the inner surface where the infection is concentrated. Internal styes tend to be more uncomfortable because the bump presses directly against the eye with every blink.
How Styes Differ From Chalazia
The bump most commonly confused with a stye is a chalazion. The key difference is pain. A stye is very painful from the start, with redness and tenderness appearing right away. A chalazion, by contrast, is usually painless at first. You might not even notice it until it grows large enough to see or feel.
Location helps, too. Styes typically sit right at the eyelid’s edge, near the lash line. Chalazia tend to develop farther back on the lid, away from the margin. A chalazion is caused by a clogged oil gland without active infection, so it grows more slowly. As it gets bigger, it can become red and mildly tender, which is when it starts to mimic a stye. But if your eyelid bump appeared suddenly with sharp pain, it’s almost certainly a stye.
What Causes Styes
The culprit is almost always Staphylococcus aureus, a common bacterium that lives on skin. When an oil gland or lash follicle gets blocked, the trapped secretions create an environment where this bacterium thrives, triggering an infection.
Certain conditions make styes more likely to recur. Blepharitis, a chronic inflammation of the eyelid margins, is one of the biggest risk factors. If you have blepharitis, the oil glands along your lash line are already prone to clogging and irritation, giving bacteria more opportunities to cause problems. Rosacea, the skin condition that causes facial redness and flushing, also increases the risk of both blepharitis and recurrent styes. If you keep getting styes, one of these underlying conditions may be driving the cycle.
Typical Timeline
A stye usually follows a predictable arc. The first sign is tenderness and slight swelling at one spot on the eyelid. Over the next day or two, the bump becomes more defined, redder, and increasingly painful. Around day three to five, a visible pus-filled head often forms. The bump then ruptures on its own, drains, and the pain drops noticeably. Full resolution, including the swelling going down completely, takes one to two weeks without any treatment.
Warm compresses can speed things up. Holding a clean, warm cloth against the closed eyelid for 10 to 15 minutes several times a day helps the blockage soften and drain sooner. Squeezing or popping a stye yourself can push the infection deeper into the eyelid, so it’s best to let it drain naturally.
When a Stye Needs Medical Attention
Most styes are harmless and self-limiting, but in rare cases the infection can spread beyond the bump into the surrounding tissue. This is called preseptal cellulitis, and it looks distinctly different from a simple stye. Instead of a localized bump, the swelling spreads across the entire eyelid and the skin around the eye socket. The area becomes deeply red and hot, and you may develop a fever.
If a stye doesn’t improve after two weeks, or if it grows very large, a doctor may need to drain it with a small incision. Signs that warrant prompt medical evaluation include fever alongside eye swelling, pain that worsens instead of improving, vision changes, or the eye itself beginning to bulge forward. In children especially, fever combined with swelling around the eye socket is a reason to seek immediate care.