A stye, also known as a hordeolum, is a red, painful lump near the edge of the eyelid that is caused by a bacterial infection of the oil glands in the eyelid. The bacterium staphylococcus is commonly responsible for most of these infections. The stye is formed when a tiny oil gland near the eyelashes becomes blocked and infected, allowing bacteria to grow inside the blocked gland. This blockage and infection lead to the formation of a red, painful bump on the eyelid, similar to a pimple or boil. Styes are often caused by bacteria infecting an eyelash follicle or eyelid gland, and individuals with long-term blepharitis are more likely to get a stye. The combination of a clogged oil gland and a certain type of bacteria is what usually causes styes.
In summary, a stye on the eyelid is primarily caused by a bacterial infection of the oil glands in the eyelid, leading to the formation of a painful red bump. It is important to seek medical attention if the stye does not improve after 48 hours or if there is redness and swelling involving the entire eyelid or extending into other parts of the face.
