A stye (also called a hordeolum) is a small, red, painful lump that grows from the base of your eyelash or under the eyelid. Most styes are caused by a bacterial infection.
There are two kinds of styes:
External hordeolum: A stye that begins at the base of your eyelash. Most are caused by an infection in the hair follicle. It might look like a pimple.
Internal hordeolum: A stye inside your eyelid. Most are caused by an infection in an oil-producing gland in your eyelid.