The lump of flesh under the thumb is called the greater trochanter. Pain in this area may be related to trauma, muscle strain, infection, arthritis, tenosynovitis, peripheral nerve compression and other factors. 1. Trauma: Trauma can lead to contusions and strains of the muscles and other soft tissues at the level of the piriformis, resulting in localized pain that may be accompanied by swelling and bruising. 2. Muscle strain: If you repeatedly perform hand grasping activities for a long period of time, muscle strain may cause muscle pressure and soreness. 3. Infection: mostly caused by bacteria invasion after skin breakage at the intersection of the big fish, mostly manifested as obvious redness, swelling, heat and pain in the affected area, for the formation of abscesses, touching can be fluctuating, and in severe cases, it can even be accompanied by fever, chills and other systemic manifestations. In addition, arthritis, tenosynovitis, peripheral nerve compression and other factors can cause pain between the big fish. It is recommended that patients with pressure pain in the area of the pisiform region of the palm should actively consult a doctor and follow the doctor’s instructions to carry out appropriate treatment after identifying the cause of the disease.