For patients with thumb cramps, the cause is seen in strain, especially if the thumb is overstressed on a regular basis, which leads to excessive strain on the tendons of the thumb, which causes spasm and contraction of the tendons, resulting in the appearance of thumb cramps. This condition is also associated with strain, which causes the tendon sheath of the thumb to be stretched repeatedly, resulting in inflammatory edema and hyperplasia of the tendon sheath, which can compress the flexor tendon and cause cramps in the thumb during flexion and extension activities. There are also cases of degeneration and osteophytes in the bone joints of the thumb that occur in middle-aged and elderly people, which can also cause cramps in the thumb when the thumb is flexed and extended and the surrounding ligaments and tendons of the joint capsule are irritated by the enlarged bone.