Sty: Symptoms & Signs

  • Medical Author:
    Melissa Conrad Stöppler, MD

    Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

Medically Reviewed on 2/25/2016

Typically, a sty produces a bump on one of the eyelid at the site of the gland that is blocked. Symptoms and signs such as

  • redness,
  • pain,
  • tenderness usually accompany the lump on the eyelid.

It may be painful to blink the eye, and excess watering or tearing can result. In some cases, there is a small, yellow spot at the center of the bump; this is a collection of pus.

Causes of a sty

There are two types of sties, hordeolum and chalazion. A hordeolum is a blockage of a sweat gland on the skin of the lid and base of the eyelashes, or one of the small sebaceous glands found at the base of the eyelashes. A chalazion is a blockage of a meibomian gland, a special sebaceous gland unique to the eyelids. These glands are located in a single row in each lid.

Blockages of either of these gland types happen if the gland's opening is obstructed for any reason. Common causes of the blockage are scar tissue, foreign substances like makeup or dust, or if there are thickened secretions, causing the material from the gland to flow slowly or not at all.


Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.

Medically Reviewed by a Doctor on 2/25/2016

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