De Quervain’s tenosynovitis is a condition in which the tendons in the thumb and wrist become inflamed, causing pain and stiffness in the base of the thumb and/or side of the wrist closest to the thumb. If De Quervain’s tenosynovitis continues without treatment, the pain may radiate further from the base of the thumb into the thumb, up the forearm, or both. Typically, symptoms should start to improve after 4 to 6 weeks of non-surgical treatment.