Causes of hand thumb joint pain are trauma, thumb tendinitis, rheumatoid arthritis and so on. 1. Trauma: If the thumb has been subjected to violence or impact, etc. caused by bone tissue or soft tissue injury, it will produce cause pain. 2. Thumb tendonitis: generally and occupationally related, long-term over-activity of the thumb caused by joint muscle strain, which leads to the occurrence of tenosynovitis, there will be thumb joint pain accompanied by joint popping. 3. Rheumatoid arthritis: rheumatoid arthritis patients with autoimmune system disorders, may involve the thumb joint aseptic inflammation leading to thumb pain, dysfunction, and even joint deformity. Hand thumb joint pain may also exist other causes, it is recommended that should go to the hospital to clarify the cause of the disease, and for the cause of the treatment.