What causes swelling and pain in the thumb?

Swelling and pain in the thumb may be caused by various factors: Soft tissue injury: Such as crush injuries or impact trauma, which may lead to impaired microcirculation around the thumb, resulting in swelling and pain, possibly accompanied by bruising and redness. 1. Infectious inflammation: For example, suppurative tenosynovitis. When a break in the skin on the thumb becomes infected with bacteria, it may cause an acute suppurative infection, manifesting as redness, swelling, heat, and pain. 2. Arthritis: Such as rheumatoid arthritis or gouty arthritis. These conditions may cause redness, swelling, heat, and pain in the thumb joint, possibly accompanied by joint stiffness and deformity. 3. Tendinitis or tenosynovitis: Due to chronic strain or trauma, the thumb may develop tendinitis or tenosynovitis, presenting as swelling, pain, and limited mobility in the joint area. If swelling and pain in the thumb persist or worsen, prompt medical attention is recommended.