The possible causes of lumps and bumps inside the thigh muscles include infection, fibrous tissue tumor, hematoma and tumor. 1. Infection: the most common cause may be infectious factors, thigh skin is susceptible to infection, such as bacterial, viral, fungal and other pathogenic microbial infections will appear in the muscle lumps, bumps and bumps, redness and discoloration of the surface of the skin and pain or pus and other symptoms of the pressure area. 2. Fibroma: Fibroma occurs inside the thigh muscle and there will be hard lumps, the surface of fibroma is smooth and the boundary is clear, although there are hard lumps when touching, but the texture is hard and there will not be pus infection. 3. Hematoma: Hematoma can be formed between the thigh muscles due to trauma and other causes of muscle injury and bleeding, and gradually become hard lumps. It can also develop into ossified myositis. It is the cause of thigh muscle ability lumps and bumps. 4. Tumor: thigh meat inside the hard lumps is not excluded is also a tumor, occurring in the femur benign and malignant tumors, growth to the muscle, can be touched in the muscle hard lumps. Thigh muscle inside lumps and bumps may also have other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.