Inner thigh depression consider muscle atrophy, muscle breakage, skin disease, scarring and so on. 1. Muscle atrophy: for example, lumbar disk herniation compressing the nerve, the disease is relatively long, causing muscle atrophy. There may also be metabolic myopathy causing atrophy of the medial femoral muscles. 2. Muscle rupture: due to trauma caused by the inner thigh muscle fiber rupture, there will be obvious local pressure and pain, depression, activity is limited. Surgery can be performed to close the broken muscles. 3. Skin disease: Skin lesions such as lupus erythematosus or degeneration of subcutaneous fat tissue may cause localized tissue depression. 4. Scarring: If the local trauma caused by the formation of scar tissue around the tissue will also be sunken. So there are many reasons for inner thigh depression, it is best to go to the hospital to check the specific cause, and further treatment under the guidance of the doctor.