A small nodule on the outer thigh may be caused by subcutaneous tissue hyperplasia, rheumatoid or rheumatoid arthritis, gout and other factors. 1. Hyperplasia of subcutaneous tissues: there are abundant soft tissues attached to the outer thigh such as muscle and adipose tissue, when the subcutaneous tissues undergo denaturation or accumulation, nodules on the outer thigh may appear, such as lipomas caused by accumulation of subcutaneous fat, fibrous tumors caused by fibroblasts, and sebaceous cysts caused by sebaceous gland clogging, etc. Commonly, there may be nodules on the outer thigh due to accumulation of subcutaneous fat. 2. Rheumatism, rheumatoid arthritis: it belongs to autoimmune diseases, which will lead to local vascular lesions in the affected joints and vasculitis, causing fibrous degeneration of local tissues, resulting in the formation of lateral thigh nodules. 3. Gout: When hyperuricemia leads to gout, gout stones may appear due to uric acid crystals deposited in the joints, and the above symptoms may also appear. There may be other reasons for a small nodule on the outer thigh, it is recommended that the patient go to the hospital in time to improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.