A stye is a small, painful lump on the inside or outside of the eyelid.

If you have a stye, your eye may also be watery and you may have a red eye or eyelid.

A stye – also called a hordeolum – usually only affects one eye, although it's possible to have styes in both eyes or to have more than one stye in the same eye. Your vision shouldn't be affected.

Types of stye

There are two types of stye. They are:

• external stye (external hordeolum) – a swelling that develops along the edge of your eyelid; it may turn into a yellow pus-filled spot that is painful to touch
• internal stye (internal hordeolum) – a swelling that develops on the inside of your eyelid; it's usually more painful than an external stye

What causes a stye?

Styes are usually caused by an infection with staphylococcus bacteria (staphylococcal infection).

Long-term blepharitis (inflammation of the eyelids) may also increase the risk of developing a stye.

Styes are fairly common and you may have at least one or two during your lifetime.

Read more about the causes of a stye. 

Treating a stye

Most styes get better without treatment within a few days or weeks.

External styes may turn into yellow spots and release pus after three to four days. Internal styes are more painful and may last slightly longer.

A warm compress (a cloth warmed with warm water) held against the eye will encourage the stye to release pus and heal more quickly.

Further treatment isn't usually needed unless your stye is very painful and isn't getting better. In this case, your GP may decide to drain it.

You should never attempt to burst a stye yourself.

Read more about treating a stye.

Complications of a stye

Your GP may prescribe antibiotics if you experience complications of a stye.

Complications can include:

• a chalazion (meibomian cyst) – which can develop if a gland in your eyelid is blocked
• preseptal cellulitis – an infection of the tissues around your eye