Styes: causes, symptoms and treatment explained

A stye is a common condition that affects the eyelid and is also known as a hordeolum. It refers to a small, painful lump, which occurs when a tiny oil gland close to your eyelashes becomes blocked and/or develops an infection. While a stye can be accompanied by a bacterial infection, styes are not usually contagious. 

Here, we will look at types of styes, symptoms and treatment. 

Types of styes

There are two types of styes: internal and external. 

An external stye develops on the outer edge of your eyelid and faces outward away from your eyeball. It can look like a pimple and is usually caused by a blocked sebaceous gland attached to the tiny cavity (follicle) that holds your eyelash. These glands produce an oily substance called sebum to prevent your eyelashes from drying out. 

An internal stye develops on the inner edge of your eyelid and faces inward towards your eyeball. It is caused by a blocked Meibomian gland. These glands produce oils that form part of your tear film ie the thin film of fluid that covers the exposed part of your eyeball to prevent it from drying out. 

What is the difference between a stye and a chalazion?

It can be quite difficult to distinguish a stye from a chalazion as a chalazion can often develop from an internal stye. 

A chalazion, also known as a Meibomian cyst, refers to the swelling of part of your eyelid due to a blocked Meibomian gland. This causes oil to become backed up inside your eyelid. Your swollen eyelid can then apply pressure to your eyeball, changing the shape of its surface (astigmatism). This can result in blurred vision; your vision will return to normal after the chalazion goes away. 

In general, a lump or swelling of the eyelid due to a chalazion develops further back from the edge of the eyelid than a stye. 

Symptoms of a stye

If you have a stye, you will have a red, tender, itchy lump on your eyelid. You may also have crusty debris along the edge of your eyelid and a watery eye; these symptoms are caused by inflammation of the eyelid (blepharitis), which can occur alongside a stye. 

If you experience persistent bouts of blepharitis, the consistency of the oil produced by your Meibomian glands can thicken, increasing the risk of your Meibomian glands becoming blocked and causing a stye. 

Who is most at risk of developing a stye?

As mentioned earlier, if you have persistent blepharitis, you are more likely to develop styes. If you have a skin condition that causes your sebaceous glands to produce more oil, such as rosacea or acne, your risk of styes is also higher.

Conditions that impair your immune system and consequently increase your risk of infections, such as diabetes, increase your risk of styes too. 

Additionally, lifestyle factors can increase your risk. If you are feeling run down or stressed and/or are not sleeping well, your immune system will be affected. With your body less able to fight off infections, your risk of styes increases. 

If you wear eye makeup, such as mascara or eyeliner on the edge of your eyelid, but do not remove it properly, your oil glands can become blocked, leading to styes. 

Getting a diagnosis

If you suspect that you have a stye, see your optician or GP. They can usually make a diagnosis after performing a physical examination of your eyelid and asking you about your symptoms and how long you have had them — a stye usually takes three to five days to form, while a chalazion can take several weeks to develop.

Depending on your age and other risk factors, your GP or optician may refer you to an ophthalmologist. This is because other conditions can cause lumps and bumps in the eyelid. 

If you are aged over 50 and have never had a stye before, it is particularly important to have your symptoms investigated to rule out cancer. A very rare form of skin cancer called sebaceous carcinoma most commonly affects the eyelid and can look like a stye. Other cancers or inflammations can also sometimes be mistaken for a stye or chalazion. 

Treatment for a stye

The first line of treatment for a stye is to apply a warm compress over your eyelid with your eye closed using a clean towel. This can help open up your glands and unblock them. However, if your stye has already caused your eye to become inflamed, it may feel too uncomfortable to apply a warm compress.

If your stye persists, your doctor may prescribe a course of antibiotics in the form of eye drops. If the infection has spread beyond your eyelid or has caused your entire eyelid to swell (preseptal cellulitis), they may prescribe antibiotics orally ie as tablets. 

For persistent styes or those that aren’t responding to other treatments, a doctor specialising in treating the eyes (an ophthalmologist) may prescribe steroids alongside antibiotics. 

Can styes recur?

If you are stressed, run-down, or have a health condition that impairs your immune system or increases oil production by your sebaceous glands, you may experience frequent styes. 

In most cases, a stye does not keep occurring in the same gland but in an adjacent or nearby gland. 

How to reduce your risk of styes

To reduce your risk of developing a stye, remove any eye makeup thoroughly and clean your face every night. 

Persistent styes can be a sign that you are stressed and it is time to make changes to reduce your stress levels and focus on your wellbeing. This may include sticking to a healthy bedtime routine so you benefit from better quality sleep and following a healthy, balanced diet high in anti-inflammatory omega oils, such as oily fish, walnuts, eggs, flaxseeds and chia seeds.