A stye is a small, painful lump that forms on the edge of your eyelid. The pus inside a stye is mostly dead white blood cells, bacteria, and tissue fluid. The bacteria are almost always Staphylococcus aureus, which lives harmlessly on your skin and in your nose until it gets trapped in an eyelash follicle or oil gland.
That trapped bacteria triggers an immune response. Your body sends white blood cells to fight the infection. The battle creates pus. When the stye comes to a head and drains, that pus is what comes out. It is not a sign that you are dirty or unhygienic. Most people carry this bacteria without any problems at all.
What Exactly Is In Stye Pus?
Pus is a byproduct of your immune system fighting an infection. It is not just dead bacteria. It is a mixture of several things your body produces during inflammation.
The main components of stye pus are:
- Dead white blood cells — primarily neutrophils that died after attacking the bacteria
- Live and dead bacteria — usually Staphylococcus aureus
- Tissue fluid — plasma that leaks from nearby blood vessels
- Dead skin cells — from the lining of the eyelash follicle or gland
- Enzymes — released by white blood cells to break down tissue
The pus is thick and yellowish because of the dead white blood cells. A specific enzyme called myeloperoxidase gives pus its color. This enzyme is released when white blood cells die and break open.
Some people wonder if stye pus is different from other pus. It is not chemically unique. Pus from a stye is the same type of pus your body produces for any localized bacterial infection. The location is what makes it feel different because your eyelid is one of the most sensitive areas of your body.
What Bacteria Cause a Stye?
Staphylococcus aureus is responsible for the vast majority of styes. This bacteria colonizes the skin and nasal passages of about 30 percent of healthy adults. It causes no problems in most cases.
The infection happens when the bacteria enters a blocked gland. Your eyelid has two types of glands. The meibomian glands produce the oily layer of your tears. The glands of Zeis are attached to your eyelash follicles. When either becomes blocked, bacteria can multiply inside and trigger an infection.
There are two main types of styes based on which gland is infected:
- External stye (hordeolum externum) — affects the glands of Zeis at the base of the eyelash. This is the more common type and usually points outward.
- Internal stye (hordeolum internum) — affects the meibomian glands inside the eyelid. This type can be more painful because it presses against the eye itself.
Some research suggests that methicillin-resistant Staphylococcus aureus, known as MRSA, is becoming a more common cause of styes. This is not a reason to panic. It does mean that recurrent or stubborn styes may need different antibiotic treatment than standard ones.
Is It Safe to Pop a Stye?
No. You should never squeeze or pop a stye. This is one of the most important things to understand about this condition.
Popping a stye can push bacteria deeper into the eyelid tissue. The infection can then spread to surrounding areas. In rare cases, this can lead to a serious condition called orbital cellulitis, which is an infection of the tissues around the eye. Orbital cellulitis requires immediate medical treatment and can threaten your vision.
Another risk is that you might not be looking at a stye at all. A chalazion is a blocked oil gland that is not infected. It looks similar to a stye but contains no pus and is not caused by bacteria. Popping a chalazion can cause scarring or introduce bacteria into a previously sterile lump.
Styes usually drain on their own within one to two weeks. When they drain naturally, the pus comes out on its own and the eyelid heals. Your job is not to force the drainage but to help it happen safely.
How Is a Stye Treated at Home?
Warm compresses are the single most effective home treatment for a stye. The evidence for this is strong and consistent across clinical guidance.
Apply a clean cloth soaked in warm water to the closed eyelid. The cloth should be warm but not hot enough to burn the skin. Leave it on for 10 to 15 minutes. Repeat this three to four times per day.
The warmth does two things. It softens the material blocking the gland, which helps the stye drain on its own. It also increases blood flow to the area, which brings more immune cells to fight the bacteria.
Most styes resolve within one to two weeks with warm compresses alone. Some research suggests that consistent warm compresses may shorten the duration of symptoms compared to no treatment.
Over-the-counter pain relievers like acetaminophen or ibuprofen can help with discomfort. Follow the dosing instructions on the package. Do not use antibiotic ointments without talking to a doctor first. Using the wrong antibiotic or using one for too short a time can contribute to bacterial resistance.
Stop wearing eye makeup and contact lenses until the stye heals. These can introduce more bacteria to the area and delay healing. Wash your hands thoroughly before and after touching your eye area.
When Should You See a Doctor for a Stye?
Most styes do not require medical attention. But certain signs mean you should see a doctor rather than continuing home treatment.
See a doctor if the stye does not improve after 48 hours of warm compresses. Also seek medical care if the stye grows rapidly, becomes very large, or interferes with your vision. Pain that worsens despite home treatment is another reason to get checked.
Signs that the infection may be spreading include redness spreading beyond the stye itself, swelling of the entire eyelid or cheek, and fever. These symptoms can indicate cellulitis, which requires prescription antibiotics.
Recurrent styes are worth discussing with a doctor. If you get styes several times per year, there may be an underlying cause. Blepharitis, which is chronic inflammation of the eyelid margins, is a common contributor. Rosacea and seborrheic dermatitis are also associated with recurrent styes.
A doctor may prescribe antibiotic eye drops or ointment for a stye that is not resolving. In some cases, a doctor may need to make a small incision to drain a stye that is not draining on its own. This is an in-office procedure done with local anesthesia. It is different from popping the stye yourself because it is done under sterile conditions with proper tools.
Can You Prevent Styes?
You cannot completely prevent styes because the bacteria that cause them live on your skin naturally. But you can reduce your risk.
Hand hygiene is the most effective prevention measure. Wash your hands before touching your eyes. This includes when you put in or remove contact lenses, apply eye makeup, or rub your eyes.
Never share eye makeup, makeup brushes, or towels. Staphylococcus aureus spreads easily through shared personal items. Replace eye makeup regularly. Mascara and eyeliner can harbor bacteria over time. Most eye makeup manufacturers recommend replacing mascara every three months.
Remove eye makeup completely before sleeping. Makeup left on overnight can block the glands in your eyelids. This creates the perfect environment for bacteria to multiply.
If you have blepharitis or dandruff, treating those conditions can reduce your stye frequency. Daily eyelid hygiene with a gentle cleanser recommended by your eye doctor can help keep gland openings clear. This is a clinical recommendation that some eye doctors suggest for people with recurrent styes, but the evidence for specific eyelid scrub products is limited.
Frequently Asked Questions
What comes out when a stye drains?
Pus comes out, which is a mixture of dead white blood cells, bacteria, and tissue fluid. It may appear thick, yellow, or white and is completely normal.
How long does stye pus take to go away?
Most styes drain on their own within one to two weeks. Warm compresses applied three to four times daily can speed up this process.
Can a stye cause permanent eye damage?
Uncomplicated styes rarely cause permanent damage. The main risk comes from squeezing the stye, which can spread infection deeper into the eye socket and require urgent medical treatment.
Are styes a sign of a weak immune system?
Occasional styes are not a sign of immune problems. Recurrent styes are more often linked to blepharitis, rosacea, or poor eyelid hygiene than to immune dysfunction.
Styes are common, uncomfortable, and almost always harmless. The pus inside them is simply your immune system doing its job. Warm compresses, patience, and good hand hygiene are the foundation of treatment. If a stye does not improve within two weeks or shows signs of spreading, see a doctor.
