Hand cramps can be caused by excessive fatigue, low blood calcium and nerve compression. 1. Excessive fatigue: when the hand is more active, it can cause excessive fatigue of muscles, tendons and other tissues, which cannot be relieved by resting, and when the hand is exerted vigorously, it can lead to spasm of muscles and tendons, and then hand cramps occur. 2. Low blood calcium: when the body’s blood calcium is low, the inhibition of sodium inward flow is weakened, which makes the neuromuscular excitability rise, resulting in muscle spasm, so that the symptoms of hand cramps occur when the hand is exerted vigorously. 3. Nerve compression: when suffering from cervical spondylosis and peripheral nerve mass, the muscle nerves innervating the hand are compressed, which can cause numbness, pain and muscle cramps in the hand. Hand cramps can also be caused by other reasons, it is recommended to go to the hospital in a timely manner, to clarify the cause of the disease for targeted treatment.