Upper Eyelid Lump: Causes, Symptoms & Treatment - Is It a Stye?

The most likely cause of a small red lump on the upper eyelid that feels tender and hot is a stye. A stye is a small, red, painful bump that forms on the edge of the eyelid. It is caused by a bacterial infection of the oil glands in the eyelid. Styes are common and usually resolve without treatment within a few days. However, if the stye is severe or does not resolve within a few days, it may require treatment with antibiotics or drainage.