A hard lump inside the back of the ear is painless and itchy and may be caused by sebaceous cysts, enlarged lymph nodes, keloid scars and other causes. It is recommended to go to the ear, nose and throat department of the hospital for a clear diagnosis. 1. Sebaceous cysts: some people have strong secretion function, local cleaning is not in place, resulting in sebaceous gland excretory ducts blocked, sebaceous cysts will be formed over time, may be long behind the ear is not itchy and painless hard lumps to the touch. 2. Enlarged lymph nodes: patients due to otitis media, scalp infection caused by repeated infections of the lymph nodes behind the ear, resulting in the gradual enlargement of the lymph nodes, which will also be manifested as hard bumps behind the ear painless and itchy. 3. Keloid: After local skin damage due to trauma, ear piercing and other reasons, there will be a large amount of connective tissue proliferation to form keloid, which also manifests as a painless and itchy hard lump behind the ear. Hard lumps behind the earlobe, it is recommended to go to the hospital ear, nose and throat consultation, clear diagnosis and follow the doctor’s instructions for treatment.