There are several causes of pain at the thumb joint. According to MedlinePlus, joint pain can affect one or more joints. The joint at the base of the thumb, also known as the first carpometacarpal joint, is a common location for joint problems and pain to manifest. The joint at the base of the thumb is one of the most important joints in the hand. Pain or dysfunction in this joint can be severely disabling.
Gout
Gout can cause pain at the thumb joint. According to the National Institute of Arthritis and Musculoskeletal and Skin Diseases, a division of the National Institutes of Health, gout is an extremely painful disorder that manifests when uric acid crystals, which are a bodily waste product, are deposited in a joint or in tissue surrounding a joint. Uric acid comes from the breakdown of purines, which are found in numerous foods, such as sweetbreads, sardines and anchovies. Uric acid crystals can cause inflammatory arthritis or joint pain, along with joint stiffness, redness and swelling, among other symptoms. Common signs and symptoms associated with gout include the following: hyperuricemia, or a high level of uric acid in the blood; joint fluid containing uric acid crystals; one or more bouts of acute arthritis; joints that are swollen, red and warm to the touch; and arthritis that develops in only one joint.
Osteoarthritis
Osteoarthritis can cause pain at the thumb joint. The Mayo Clinic website states that osteoarthritis, also known as degenerative joint disease, is the most common type of arthritis. Osteoarthritis manifests over time, as joint cartilage wears down. Although the condition can affect any joint in the body, it often targets the joints of the hands, hips, knees, neck and lower back. According to the Mayo Clinic website, there is no known cure for degenerative joint disease, although there are many treatments that can blunt osteoarthritis-related pain and improve a person's ability to perform activities of daily living. Common signs and symptoms associated with osteoarthritis include the following: joint pain at rest or with movement; joint tenderness when pressure is applied to the affected joint; joint stiffness that's worse upon waking; reduced joint flexibility and range of motion; and the presence of bone spurs, or osteophytes, which may be seen on an X-ray of the affected joint.
Rheumatoid Arthritis
Rheumatoid arthritis can cause pain at the thumb joint. According to NIAMS, rheumatoid arthritis is an inflammatory condition that's characterized by joint pain, swelling, stiffness and dysfunction. Rheumatoid arthritis is an autoimmune disease, which means that a person's immune system attacks the synovial membrane that lines the joints. NIAMS states that rheumatoid arthritis usually lasts for a lifetime, although the expression of the disease ranges from mild to severe, depending on the individual. Many people experience periods of mild-to-moderate joint discomfort between periods of acute flare-ups. In some people, however, rheumatoid arthritis-related symptoms are constant. Common signs and symptoms associated with rheumatoid arthritis include the following: joint inflammation that targets the wrist and carpometacarpal finger joints, fatigue and joint stiffness.
