The shaking of the left thumb may be caused by neuromuscular spasm due to overexertion and calcium deficiency, so pay attention to rest, massage, hot compresses and calcium supplements. It may be caused by cervical spondylosis, which leads to compression of the nerves in the upper limbs, and can be treated with nerve-nourishing drugs. It may also be due to hyperthyroidism, which causes finger tremors and is accompanied by panic attacks, weight loss, and goiter. If the hyperthyroidism is controlled in time, it can be improved. Tremors caused by Parkinson’s disease can be treated with dopamine agonists, such as methyldopa.