When a problem feels embarrassing, it is easy to think you are the only one dealing with it. You are not alone, and many people go through the very same thing.
This photo shows a large, round swelling on a woman’s upper back, right next to the shoulder blade. The skin over it is tight, red and a little shiny.
A lump like this is most often an epidermoid cyst. It starts when a hair follicle or pore becomes blocked and a small sac under the skin slowly fills with keratin.
The upper back is one of the most common places for these cysts, because the skin there is thick, has many oil glands and is hard to see and clean.
When the cyst becomes inflamed, it can grow quickly, feel warm and sore, and make it uncomfortable to lean back against a chair or lie on that side.
