By an infection of oil glands in the eyelid. It is actually an abscess filled with pus and is usually caused by a staphylococcus bacteria eye infection.
A stye or hordeolum is a small, painful lump on the inside or outside of the eyelid. It is actually an abscess filled with pus and is usually caused by a staphylococcus bacteria eye infection. Styes are common with most people experiencing one or two of them at some stage in their life. Styes are usually caused by staphylococcal bacteria, which often live right on the skin surface. Our bodies are coated with billions of friendly bacteria that coexist with us. When the conditions are just right the bacteria feast on dead cells and other debris, resulting in the tender pimple. Stye Causes. Styes are usually caused by infections of the oil glands in the eyelid. Very frequently, they are infected by bacteria, most commonly Staphylococcus bacteria. Seborrhea (excessive oily discharge from the glands) may increase the likelihood of developing one of these infections. Usually the bacteria grow in the root (follicle) of an eyelash. An internal hordeolum is caused by infection in one of the tiny oil glands inside the eyelid. A chalazion forms when an oil gland in the eyelid becomes blocked. If an internal hordeolum doesn't drain and heal, it can turn into a chalazion. Most will go away on their own without treatment. 1  A stye is an infection that causes a tender red lump on the eyelid. 2  Most styes occur along the edge of the eyelid. 3  When a stye occurs inside the eyelid, it is called an internal hordeolum (say hor-dee-OH-lum). A sty is caused by an infection of oil glands in the eyelid. The bacterium staphylococcus is responsible for most of these infections. 1  Symptoms. 2  Risk factors.  About styes. A stye is a swelling on your eyelid, usually caused by an infection of one or more of the eyelash follicles (the root of the eyelash) in your eyelid. Styes can appear on the outside of the eyelid (an external stye) or the inside of the eyelid (an internal stye). The medical term for a stye is a hordeolum A stye (or sty) is an acute infection of the secretory glands of the eyelids. Frequently, bacteria can enter and infect an eyelid oil gland, which are present in both the upper and lower eyelids, causing increased inflammation, pain, and redness of the eye, and even redness of the surrounding eyelid and cheek tissue. Hordeolum and Stye ». A hordeolum (ie, stye) is a localized infection or inflammation of the eyelid margin involving hair follicles of the eyelashes (ie, external hordeolum) or meibomian glands (ie, internal hordeolum). An external stye or sty /ˈstaɪ/ , also hordeolum /hɔrˈdiːələm/ , is an infection of the sebaceous glands of Zeis at the base of the eyelashes, or an infection of the apocrine sweat glands of Moll. External styes form on the outside of the lids and can be seen as small red bumps.  Styes are usually caused by a combination of a clogged oil gland and staphylococcal bacteria, which often live right on the skin surface. Our bodies are coated with billions of friendly bacteria that coexist with us. When the conditions are right, the bacteria become overabundant, resulting in the tender pimple. A stye is a pimple or abscess that forms in either the upper or lower eyelid. It is an inflammation caused by blockage of an oil duct and bacteria that normally live on the surface of the eyelid without any problems. Some germs can get trapped along with dead skin cells along the edge of the eyelid. A sty is a bump that forms on or in the eyelid as the result of a blocked gland. The word sty can also be spelled stye. There are two distinct types of styes: hordeolum and chalazion. Each has different causes and treatments. A hordeolum is a blockage of one of the sweat glands or oil glands found in the skin of the eyelid, while a chalazion is a blockage of a meibomian gland, which is a special oil gland unique to the eyelids.
http://www.webmd.boots.com/eye-health/guide/stye-symptoms-diagnosis-treatment http://www.emedicinehealth.com/sty/page2_em.htm http://www.webmd.com/eye-health/tc/styes-and-chalazia-topic-overview http://www.mayoclinic.org/diseases-conditions/sty/basics/causes/CON-20022698 http://www.bupa.com.au/health-and-wellness/health-information/az-health-information/stye http://www.emedicinehealth.com/sty/article_em.htm https://en.wikipedia.org/wiki/Stye http://www.webmd.com/eye-health/understanding-stye-basics http://www.medicinenet.com/sty_stye/article.htm
what causes stye