By Mayo Clinic Health System staff
Have you ever woken to discover a red, painful lump near the edge of your eyelid? This lump, which can develop quickly or overnight, is called a sty. It may look like a pimple or boil and be filled with pus.
A sty usually forms on the outside of the eyelid but could also form on the inner part of the eyelid. It may be extremely painful, cause your eyelid to swell and can cause you significant concern.
What is a sty?
A sty, also called a hordeolum, is caused by blocked oil glands in your eyelid. Meibomian glands in your eyelids naturally release oil, which is an important component to trap the tears on your eyes. If these glands become blocked, bacteria can grow. Our lids have naturally occurring bacteria to keep our eyes healthy. A sty can form if you have an overgrowth of bacteria at the same time as blocked glands.
Developing a sty is quite common and impacts people of all ages. Yet, people who have dry eyes or eyelid disease are more prone to sties. Other risk factors include wearing contact lenses or using old or expired makeup.
What is the treatment for a sty?
In most cases, a small sty doesn't require specific treatment and should go away on its own within a week. Applying a warm compress for 5 to 10 minutes can help with pain and swelling, as well as allowing those blocked glands to better express. Take care to keep the site clean, and don't use contact lenses or makeup during this time. Wash your hands often, and don't try to pop or squeeze the pus from a sty. Doing so can cause the infection to spread or worsen scar formation. If an active infection is occurring with the sty, you will need oral antibiotics to help the healing process.
When is a sty cause for concern?
While most sties go away without treatment or evaluation, recurring or medium-to-large sties can be a sign that your eyelids are unhealthy. Ongoing sties can damage the Meibomian glands, which decreases the oily layer. This leads to an increase in evaporation of your tears resulting in dry eye symptoms. Dry eye syndrome can get worse over time and become severe enough that available treatments are not able to help.
If you have recurring or large sties that do not go away in a few days, it's important to visit a health care provider to discover if they are caused by an underlying eyelid dysfunction.