Hard lumps on the thighs may be caused by epidermal cysts, boils, lipomas and other diseases, and can be referred to dermatology, general surgery and other departments for the cause. 1. Dermatology: If the hard bumps on the thighs are accompanied by redness, swelling, pain, tenderness and other symptoms, epidermal cysts, boils and other diseases are most likely to be considered. It is recommended that patients go to the dermatology department to find out the cause of the disease. 2. General surgery: patients with hard lumps on the thighs, there is no physical discomfort at the beginning, with the development of the disease, the lumps can gradually become larger, when pushing the base of the tumor body can make the skin appear orange peel-like texture, most often considered to be caused by lipoma. Patients are advised to go to the general surgery department. There are many reasons that lead to hard lumps on the thighs, and it is recommended that patients go to regular hospitals to find out the causes of the disease.