A stye, also known as a hordeolum, is a painful and inflamed bump or pimple that typically forms on the eyelid, near the base of an eyelash or in an oil gland.
Styes are usually caused by a bacterial infection, often involving the bacterium Staphylococcus aureus.
They can develop on either the outside (external stye) or inside (internal stye) of the eyelid. Symptoms may include redness, swelling, tenderness, and a feeling of discomfort.
Styes often resolve on their own, but warm compresses and good eyelid hygiene can help alleviate symptoms. In some cases, medical treatment may be needed, particularly if the stye persists or worsens.