Shaking when the thumb flexes can be seen in calcium deficiency, as well as in conditions such as hyperthyroidism. Flexion of the thumb requires contraction of the finger muscles, which also tightens the ligaments and tendons. If there is a calcium deficiency, the excitability of the nerves increases, and the muscles and tendons are stimulated, then symptoms such as shaking will occur, especially after labor. Hyperthyroidism, on the other hand, is prone to fine tremor of the hands, need to do serum electrolytes, and thyroid function to determine, calcium deficiency can be treated with calcium carbonate chewable tablets, hyperthyroidism can be treated with drugs such as methimazole.