Merriam-Webster Online Thesaurus
Stye (Wikipedia)
This article is about the swelling of an eyelid. For other uses, see Sty (disambiguation).
Synonyms sty, hordeolum
An external stye on the upper eyelid
Classification and external resources
Specialty Ophthalmology
ICD-10 H00.0
ICD-9-CM 373.11
DiseasesDB 12583
MedlinePlus 001009
eMedicine emerg/755
MeSH D006726

A stye, also known as a hordeolum, is an infection of an oil gland in the eyelid. This results in a red tender bump at the edge of the eyelid. The outside or the inside of the eyelid can be affected.

The cause of a stye is usually a bacterial infection by Staphylococcus aureus. The internal ones are due to infection of the meibomian gland while the external ones are due to an infection of the gland of Zeis. A chalazion on the other hand is a blocked oil gland without infection. They are typically in the middle of the eyelid and non painful.

Often a stye will go away without any specific treatment in a few days or weeks. Recommendations to speed improvement include warm compresses. Occasionally antibiotic eye ointment may be recommended. While these measures are often recommended evidence to support them is poor. The frequency at which they occur is unclear. They may happen at any age.