An ingrown hair bump, or cyst, extends from your body’s surface and deep underneath it. It often looks like a red pimple with one hair on its surface, but other types can look different and ...

Lumps can form under the skin for many reasons, including cysts or swollen lymph nodes. Often they don’t require treatment, but if they change in size or appearance, contact a doctor for an exam.

This helps your doctor to better diagnose the size, shape, and number of nodules, whether they might be cysts or something more serious. A sonogram can also help your doctor perform a biopsy.