If a patient has pain in the thigh fossa, the causes include knee degeneration, posterior meniscal horn injury, ligament injury in the thigh fossa area, and inflammatory stimulation, etc., as follows: i. Knee degeneration: osteoarthritis tends to lead to increased pressure inside the knee joint, causing swelling and pain in the thigh fossa area. Second, the posterior horn of the meniscus injury: easily lead to the thigh fossa area ligament, joint capsule stimulation, triggering the thigh fossa area pain. Third, the thigh fossa area ligaments, joint capsule strain and injury: will also cause the thigh fossa area with pain symptoms. Inflammatory stimulation: Inflammatory stimulation in the thigh fossa, such as infection, will lead to significant redness, swelling, heat and pain in the thigh fossa. Therefore, after the patient has pain in the thigh fossa, it is important to consult a doctor to see what causes it. Treating the cause will help to reduce and recover from the pain. In case of thigh pain, it is important to avoid standing for a long time and avoid repeated squatting and running and jumping activities to avoid aggravating the pain in the thigh fossa.