A stye, medically known as a hordeolum, is an acute bacterial infection affecting the oil or sweat glands within the eyelid. This condition typically arises when the sebaceous glands of Zeis or Moll near the eyelash follicle, or the deeper Meibomian glands, become blocked and subsequently infected, most often with Staphylococcus aureus. The immediate physical manifestation is a localized, painful, red bump along the eyelid margin. A stye is essentially a localized abscess that forms as the body attempts to contain the infection.
The Typical Natural Progression
The majority of styes follow a predictable, self-limiting course, resolving without medical intervention. As the stye progresses naturally, the body attempts to contain the bacterial infection. This involves an acute inflammatory reaction leading to the formation of a localized abscess, or pocket of pus. The stye usually comes to a head, appearing as a small yellowish spot at the center of the swelling over three to five days. The pressure from the accumulating pus eventually causes the abscess to spontaneously rupture and drain. Once drainage occurs, the pain and swelling subside quickly, and the eyelid begins healing. Complete resolution typically takes between one to two weeks.
When a Stye Worsens
Leaving a stye untreated carries the risk of the infection evolving into more complicated or chronic issues. One frequent outcome of a stye that fails to drain is the development of a chalazion. If the infection subsides but oily secretions remain trapped, the acute inflammation transitions into a chronic, non-infectious granulomatous reaction. This results in a firm, rubbery, and often painless lump deeper within the eyelid that can persist for months and may require specific treatment.
The bacterial infection can spread beyond the glandular structure into the surrounding eyelid tissues, known as preseptal or periorbital cellulitis. This complication is characterized by rapidly increasing, diffuse redness and swelling that extends across the entire eyelid and sometimes onto the cheek. In rare instances, the infection can breach the orbital septum and progress to orbital cellulitis, a more severe condition involving the tissues behind the eye. This deeper spread can cause systemic symptoms and is considered a serious medical event.
A large stye, especially an internal hordeolum, can mechanically interfere with vision. The swelling and mass can press against the cornea, causing a temporary distortion of its curvature known as induced astigmatism. This pressure results in temporary blurred or distorted vision until the swelling decreases. Persistent pain, increased tenderness, and sensitivity to light (photophobia) are also signs that the localized inflammation is progressing rather than resolving.
Signs That Require Medical Care
Distinct symptoms signal the need for professional medical consultation, indicating the stye is not resolving or has developed a complication. A medical evaluation is warranted if the swelling and pain do not improve within one to two weeks, or if symptoms actively worsen after the first few days.
Other signs requiring prompt medical attention include:
- Rapidly increasing redness or swelling that spreads beyond the eyelid margin to involve the entire lid or extends to the cheek indicates a spreading infection like cellulitis.
- Systemic signs, such as a fever or chills, suggest the infection has moved beyond the localized area and may require oral antibiotics.
- Any change in vision, including new blurriness, double vision, or the stye physically obstructing the visual field.
- If the stye begins to bleed, or if the same area experiences frequent and recurring styes.