Painful thumb joints make many daily tasks uncomfortable. Causes of thumb joint pain include various injuries and conditions that affect the bones and soft tissue. Pain may occur immediately after trauma to your thumb, or it may come on more gradually. Because serious medical conditions, such as infection, can cause joint pain, see your doctor to determine the cause of your thumb pain.
Arthritis is a frequent cause of thumb joint pain. According to a study published in April 2011 in the journal "Rheumatology," the first and second joints of the thumb are the most common hand joints affected by osteoarthritis. Cartilage provides soft tissue padding between the bones in your thumb joints. Osteoarthritis causes this cartilage to wear down. The bones eventually rub together, causing pain in the thumb joint. Rheumatoid arthritis is another condition affecting the thumb joints. This disease process causes your body to mistakenly attack your healthy joints, breaking down the soft tissue.
Joint pain caused by thumb arthritis gradually worsens. Fine motor activities, such as writing, and pinching tasks, such as carrying a dinner plate, cause sharp joint pain. As the condition progresses, you may feel aching pain in your thumb joints at rest.
Fractures in your thumb bones can also cause pain. The most common fracture involving a thumb joint is called a Bennett fracture. This injury affects the thumb joint approximately 1 inch above your wrist. In addition to pain, you may also have swelling and bruising around the joint. Fractures in the thumb joints typically occur from a fall on your outstretched hand, sports activities or trauma to the thumb. The pain is sharp, and increases when you try to use your thumb.
Thumb fractures can be serious. Fractures at the end of a bone may limit your ability to move the joint. You may need surgery to stabilize the bone to keep it in the correct position as it heals.
Tendons connect the muscles to the bones in your thumb. Tendons attach close to your joints to bend and straighten the tip and base of your thumb, and to move the base from side to side. When these tendons are overstretched or overworked, they typically cause pain. Inflammation causes the tendon to swell, increasing friction and pain as you move your thumb. Trauma and overstretching can cause the tendon to tear. These injuries typically affect the tendons that bend and straighten the tip of your thumb, causing pain at the joint closest to the tip of your thumb.
If your tendon is completely torn, the pain may subside after the initial injury. Later, you will notice you cannot bend or straighten the joint, depending on which tendon is torn. Seek medical attention immediately if you are unable to move your painful thumb joint because torn tendons typically need surgery.
Ligaments attach bone to bone, keeping your joints stable. Trauma or overstretching can damage thumb ligaments. Two main ligaments support the base of your thumb -- the ulnar collateral and radial collateral ligaments. The ulnar collateral ligament is more commonly injured. This injury is often called "skier's thumb" because such an injury is common to skiers: the thumb is forced away from the hand as the skier's hand lands on the ski pole or the ground.
Ligament injuries typically cause sharp pain at the joint where the thumb meets your hand. Pain increases with activities that require pinching. Although stretched ligaments often heal with splinting and rest, severe tears may require surgery.