A stye looks like a small, red, pimple-like bump on the edge of your eyelid. It typically forms right at the base of an eyelash and often develops a visible white or yellow pus spot at its center, much like a whitehead. The surrounding eyelid skin turns red and swollen, and in some cases the swelling spreads across the entire lid.
External vs. Internal Styes
Most styes are external, meaning they form on the outer edge of your eyelid where your lashes grow. These are the easiest to spot: a tender, raised bump that faces outward and looks strikingly similar to an acne pimple. You can usually see the redness and swelling clearly in a mirror, and the bump sits right along the lash line.
Internal styes develop on the inner surface of your eyelid, facing your eyeball. Because of their location, you may not see a visible bump at all from the outside. Instead, you’ll notice general eyelid swelling, redness, and a deep, aching tenderness when you blink or press on the lid. If you gently flip the eyelid, you may see a red, inflamed area on the inner surface. Internal styes form when an oil gland embedded inside the lid becomes infected.
How a Stye Changes Over Time
A stye doesn’t appear fully formed. It develops over one to two days, starting as a small area of tenderness and redness along the lid margin. During these first hours, it may just feel like an irritated spot with mild swelling, and you might not see a defined bump yet.
Over the next day or so, the bump becomes more distinct: a warm, swollen, red lump that’s painful to touch. This is the peak stage, when the stye is most noticeable. Many styes develop a small pus-filled head at their center, appearing as a tiny white or yellowish dot on top of the red bump. The entire eyelid can look puffy and discolored, sometimes enough that the eye appears partially shut.
As it heals, the stye typically drains on its own. The pus spot may rupture, releasing a small amount of fluid, after which the pain drops quickly and the swelling begins to shrink. Most styes resolve within a week or two. Warm compresses held against the lid for 10 to 15 minutes several times a day speed up this drainage process.
Stye vs. Chalazion
A chalazion is the bump most commonly confused with a stye, and knowing the visual differences helps you figure out what you’re dealing with. A stye is very painful, sits right at the lash line, and often has a visible pus spot. A chalazion is usually not painful, forms farther back on the eyelid (away from the lash edge), and looks like a firm, round bump under the skin without an obvious head. Chalazia are caused by a blocked oil gland rather than a bacterial infection.
Another key difference is swelling pattern. A stye frequently makes the entire eyelid puffy and inflamed. A chalazion rarely causes that kind of widespread swelling. It tends to stay localized as a discrete, rubbery lump. Sometimes a stye that doesn’t fully drain can turn into a chalazion over time, transitioning from a painful red bump into a painless, harder nodule.
Warning Signs That Look Different
A straightforward stye stays localized to one spot on the eyelid. If the redness and swelling begin spreading well beyond the bump, across the entire eyelid and into the skin around the eye socket, that pattern can signal periorbital cellulitis, a skin infection that needs prompt treatment. The swelling in cellulitis looks more diffuse and “washed out” across a broad area rather than concentrated in a single bump.
Watch for these specific changes that suggest something beyond a normal stye: a fever alongside the eye swelling, pain when moving the eye itself (not just the lid), any changes in vision, or the eye starting to bulge forward. In children especially, a fever combined with swelling around the entire eye socket warrants an emergency visit. A regular stye, by contrast, stays painful but contained, doesn’t cause fever, and doesn’t affect your ability to see or move your eye.
What to Expect While You Have One
Beyond the bump itself, styes commonly cause watery eyes, a gritty or scratchy sensation, and sensitivity to light. The eyelid may feel heavy or look droopy from swelling. Crusty debris can collect along the lashes, particularly after sleeping, making the eye feel stuck shut in the morning.
Styes are not contagious through casual contact, but the bacteria that cause them can spread from one eye to the other if you touch the stye and then rub your other eye. Avoid squeezing or popping the bump. Forcing the pus out can push the infection deeper into the lid tissue. Letting it drain naturally, or coaxing it with consistent warm compresses, gives you the fastest and cleanest resolution. If a stye hasn’t started improving after about a week, or if it keeps growing larger, a doctor can drain it with a small procedure in the office.