chalazion

pathology

Written by

The Information Architects of Encyclopaedia Britannica

Last updated

July 23, 2026

Quick Summary

A chalazion is a painless, chronic swelling that forms in the eyelid due to inflammation of a meibomian gland. While sometimes appearing without a clear cause, it can also develop as a lingering effect of an internal sty.12

Sties, on the other hand, are acute, painful infections of eyelid glands. External sties affect sebaceous glands in the eyelid margin, often caused by Staphylococcus bacteria, presenting as a boil-like swelling. Internal sties result from inflammation of meibomian glands and can be more painful due to pressure against the eyeball.12

Both conditions are typically treated with warm compresses and massage. Persistent or severe cases may require surgical intervention. Chronic eyelid inflammation, such as blepharitis, can contribute to recurring sties and chalazions.12

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

2 Britannica Sources

Ask Britannica AI about this topic

Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.

sty
…sty is sometimes called a chalazion, although the latter term is usually reserved for a painless chronic swelling of the meibomian gland. A chalazion sometimes appears without apparent cause and sometimes as an aftereffect of an internal sty.
Read More
…sty is sometimes called a chalazion, although the latter term is usually reserved for a painless chronic swelling of the meibomian gland. A chalazion sometimes appears without apparent cause and sometimes as an aftereffect of an internal sty.
Read More