Thickening of fingers, i.e. pestle finger, is mainly due to the lack of oxygen in the distal limb, which can be seen in rheumatoid arthritis, scleroderma, osteoarthritis, finger tenosynovitis, lung tumors and other kinds of diseases, but does not belong to the precursor of lung cancer. 1. Rheumatoid arthritis: it is an autoimmune disease that can lead to deformities and inflammation of finger joints, such as hand swelling and morning stiffness. 2. Scleroderma: it is a common connective tissue disease, which will cause hardening and swelling of fingers and other parts of skin. 3. Osteoarthritis: common in middle-aged and old people, due to degenerative changes in the bone, causing swelling and stiffness of the finger joints. 4. Finger tenosynovitis: This is a disease of the locomotor system, which can cause tough nodules and lumps near the finger joints, and thickening. 5. Chronic lung diseases: such as bronchial dilatation, tuberculosis and lung abscess, silicosis, tuberculosis and mediastinal tumor lung cancer may cause pestle finger. There are many reasons for the thickening of fingers, and lung diseases such as lung cancer cannot be ruled out. It is recommended to go to the hospital for a clear diagnosis and treatment so as not to delay the condition.