A hard lump at the root of the middle finger of the palm may be associated with tenosynovitis, tendon sheath cysts, inflammation of the flexor tendon and other causes. 1. Tenosynovitis: When the tendon here is subjected to excessive friction for a long time, it can lead to injurious inflammation of the tendon and tendon sheath, forming tenosynovitis. Symptoms such as localized swelling, pain, and dysfunction may occur. 2. Tendon sheath cysts: usually caused by exertion, cold, weight bearing, or excessive finger and wrist activities. This chronic injury leads to an increase in synovial fluid in the synovial cavity, forming tendon sheath cysts. It can be treated with topical Futenacin or Yunnan Baiyao spray, reduce excessive finger and wrist activities, and avoid exertion and cold. 3. Inflammation of flexor tendon: when the middle finger is often forcefully contracted or rubbed, it stimulates the local flexor tendon, which leads to local inflammation and hard lumps, and obvious pain can appear when pressing here. 4. Others: such as sebaceous cysts, fibromas, lipomas, etc., can lead to a hard lump at the root of the middle finger. If the symptoms can not be relieved, it is recommended to go to the hospital for consultation and targeted treatment, so as not to delay the condition.