Eye styes: causes, symptoms, types and treatment

A stye is a painful, red bump on the edge of the eyelid. This guide explains what causes styes, the symptoms to look out for, the two types and how they are treated.

What is an eye stye?

A stye, also spelt sty and known medically as a hordeolum, is an inflammation of the eyelid caused by a small pus-filled spot (pustule). It is a localised infection of the lid, most often caused by Staphylococcus bacteria.

The infection can start in one of the tiny oil glands inside the eyelid (an internal hordeolum) or at the base of an eyelash (an external hordeolum). The lump looks like a boil or pimple and is red and painful. Most styes form on the outside of the eyelid, but some appear on the inside.

Things to know about styes

• The first symptoms are pain, swelling, redness and tenderness.
• Styes do not usually affect your vision.
• They are caused by Staphylococcus bacteria.
• They develop quickly.
• Most styes heal by themselves.
• Never try to "pop" a stye.
• Styes can come with other eye problems.
• They usually affect only one eye at a time.
• Common home remedies are a warm compress and an over-the-counter pain reliever.
• See an eye doctor if a stye affects your vision or lasts longer than a week.

How styes heal

Most styes heal on their own within a week, without medical treatment. External styes, those not inside the eyelid, can fill with pus and turn yellow. Internal styes, inside the eyelid, are usually more painful.

A warm, moist compress applied gently to the stye helps the pus drain and eases the pain and swelling. Styes can come back.

Causes of eye styes

Common triggers include:

1. Using make-up after its expiry date.
2. Not cleaning your eyes and removing make-up before bed.
3. Not disinfecting contact lenses before putting them in.
4. Handling contact lenses without washing your hands properly first.

Styes are more common in teenagers, but they can affect anyone at any age. Poor nutrition and lack of sleep also contribute.

Styes can sometimes develop as a complication of blepharitis, an inflammation of the eyelids. Blepharitis is usually caused by a bacterial infection, and occasionally occurs with rosacea, an inflammatory skin condition that mainly affects the face.

Symptoms of eye styes

A stye causes a small, painful red lump on the eyelid that can make the eye water and turn red. It can look like a pimple. Styes rarely affect both eyes at the same time; usually only one eye is affected, and it is very uncommon to have more than one stye in an eye.

Symptoms can include:

• a lump on the eyelid, swelling of the eyelid, pain, redness and tenderness
• a burning sensation, drooping of the eyelid and itching
• blurred vision, mucus discharge and sensitivity to light
• watering, discomfort when blinking and a constant feeling that something is in the eye

Types of eye styes

There are two types of stye:

• External stye (external hordeolum): forms along the outer edge of the eyelid, at the base of an eyelash. It may turn yellow, fill with pus and hurt to the touch.
• Internal stye (internal hordeolum): forms in one of the oil glands inside the eyelid. It is usually more painful than an external stye.

Treatment and when to see a doctor

Most styes need nothing more than home care: a warm, moist compress applied gently, keeping the eyelids clean, and an over-the-counter pain reliever if needed. Don't squeeze or pop the stye, and follow good make-up and contact lens hygiene to lower the chance of another one.

See an ophthalmologist (eye specialist) if the stye affects your vision, lasts longer than a week, keeps coming back or comes with other eye problems. An eye doctor can confirm the diagnosis and check for related conditions such as blepharitis. For sudden or severe eye symptoms, read when to visit an eye hospital immediately.