If you’ve ever had a sty, you know the pain and irritation it causes. A lump on the eyelid appears due to a blocked sebaceous gland and usually goes away within a few days, but it may persist, causing serious inconveniences.

If a sty pops up often or persists for a long time, it can be a symptom of sebaceous gland carcinoma. If you notice that it doesn’t heal or appears in the same place, it’s time to visit a doctor.