Bumps that appear on the outside of the thighs and are raised and hard may be related to sebaceous cysts, psoriasis, and common warts. 1. Sebaceous cysts: a kind of retention cyst formed when the sebaceous gland ducts are blocked and sebum secretion cannot be discharged normally, mainly manifested as a small lump slightly protruding from the skin, with no pain when pressed locally. 2. Psoriasis: a skin disease related to autoimmune abnormalities, environmental factors and genetic factors, mainly manifested in the clinic as red plaques covered with scales, protruding from the skin surface. 3. common warts: is due to infection of human papilloma virus and lead to a skin disease, in the clinical mainly for the soybean size or larger gray-brown, brown or skin-colored pimples, the surface is rough and uneven, can be seen in the black spots, touch the hard. Due to the complexity of the etiology of the disease, the specific situation, need to ask the doctor for a face-to-face consultation.