If you have a sore lump on your upper or lower eyelid margin, it could be a chalazion or stye. Both conditions can appear very similar, but they occur due to different reasons. 

Please continue reading to learn more about styes and chalazia, including how to tell them apart, how to treat them, and how to lower your risk of developing them. 

What is a stye? 

A stye (medical term: hordeolum) is a painful red bump that develops on your upper or lower eyelid. Most styes are caused by bacterial infections. 

The stye can grow on the outer eyelid at the base of an eyelash due to a bacterial infection of the hair follicle. This is called an external hordeolum or external stye. 

A stye can also develop inside the eyelid due to a bacterial infection of an oil-producing gland. This is called an internal hordeolum or internal stye. 

Most people develop a stye on one side, but you can occasionally get styes on both eyelids at the same time. 

What is a chalazion? 

A chalazion is a swollen lump on the eyelid margin. It occurs when tiny meibomian glands (oil-secreting eyelid glands) become clogged. Sometimes, chalazia develop from internal styes. 

What are the symptoms of an upper or lower eyelid chalazion or stye?

Symptoms of a stye

• A painful red bump at the edge of the eyelid and base of the eyelashes.
• A pimple or pus spot in the center of the bump.
• Possible swelling of the entire eyelid.
• Crusting along the eyelid margin.
• Grittiness (a scratchy feeling like something is in your eye).
• Sensitivity to light.
• Tearing.

Symptoms of a chalazion

• A painless pea-like lump on the eyelid that may feel sore or tender.
• A swollen eyelid (it is rare for the entire eyelid to be swollen, however).
• Blurred vision (if a larger chalazion presses on the eye).

How do you tell if it's a chalazion or stye?

It’s not always easy to tell the difference between a stye versus chalazion. However, a key difference is that a stye is very painful while a chalazion is not usually painful. Also, styes occur at the edge of the eyelid, arising from the eyelash follicles. On the other hand, chalazia develop further back on the eyelid due to blocked meibomian glands (oil glands). Another difference between a stye and chalazion is that swelling of the entire eyelid is more commonly seen with a stye and is less likely with a chalazion.

Which is worse, stye or chalazion?

A stye is a painful lump caused by an infection of the eyelash follicle. A chalazion occurs due to meibomian gland dysfunction (blockage of an oil gland due to trapped oil secretions). Both can cause redness and swelling of the eyelid, but a stye is usually much more painful. 

What are the risk factors for a chalazion and stye in the upper and lower eyelids?

Anyone can develop a stye & chalazion. However, the risk is higher if: 

• You have blepharitis (chronic inflammation of the eyelid glands).
• You’ve had a stye or chalazion in the past. 
• You have skin conditions like seborrheic dermatitis, acne, rosacea.
• You have medical problems such as diabetes.

What is the treatment for a stye and chalazion?

Warm compresses

A warm compress and gentle massage with a clean finger can help open up and drain a blocked oil gland that is causing a chalazion. Warm compresses can also help to relieve stye symptoms. To apply a warm compress, hold a clean washcloth soaked in hot water to your eyelid for 10-15 minutes. Keep soaking the washcloth in hot water from time to time to keep it warm. Do this 3-5 times a day for symptom relief.

Medicated pads and baby shampoo

A pre-moistened medicated cleansing wipe can help relieve symptoms of a stye on the eyelid caused by infection. Medicated cleansing wipes can also give you relief from chalazion symptoms due to clogged oil produced by a meibomian cyst. 

Antibiotics

If your eye doctor feels the lump on your eyelid is a stye caused by an infection, they may prescribe an antibiotic ointment. Eye drops are usually not necessary. 

Steroid injections

A larger chalazion may need to be treated with a steroid shot (cortisone injection) to bring down the swelling.

Surgical drainage

If a stye or chalazion does not go away with medical treatment or is affecting your vision, it may require treatment surgically, meaning it may need to be drained through a small incision. This procedure is done in the doctor’s office using local anesthesia.

Biopsy

If you get recurrent styes or chalazia, your eye doctor may perform a biopsy. This involves removing a small tissue sample from your eyelid to make sure there is nothing more serious going on. 

What happens if a stye is left untreated? 

An infected stye can be very painful. If left untreated, an internal stye can develop into a chalazion.  

What happens if a chalazion is left untreated? 

If a chalazion is left untreated, it can grow in size and press upon your eye, causing eyelid swelling and blurry vision. A chalazion usually heals within a week with home treatment. Without treatment, it can take much longer, 4-6 weeks, for the meibomian gland to open up. Also, an untreated chalazion puts you at risk of developing another one. 

How to prevent chalazia and styes?

The best way to prevent styes and chalazia is to practice good hygiene. 

• Wash your hands before touching your eyes or removing contact lenses.
• Wash your face before going to bed to remove dirt and makeup. 
• Replace eye makeup every 3 months.
• If you get recurrent styes or chalazia, see your eye doctor for an evaluation. 
• Do not pop or squeeze a stye or chalazion, as this can spread the infection.
• Avoid wearing contact lenses and eye makeup if you have a stye or chalazion.
   

References:

1. https://www.aao.org/eye-health/diseases/what-are-chalazia-styes
2. https://my.clevelandclinic.org/health/diseases/17657-chalazion
3. https://my.clevelandclinic.org/health/diseases/17658-stye