Hand cramps can be a result of a calcium deficiency. Medically speaking, low calcium can cause muscle twitching. When calcium is low in the blood, it can cause involuntary muscle contractions in the fingers, calves or other areas, which can manifest as finger or toe twitches. However, not all finger twitches are caused by low calcium. Sometimes emotional patients, such as quarrelsome patients who are so angry that their hands shake or their hands cramp, and patients who are emotionally anxious or nervous, may also have finger twitches. This situation is related to the excessive excitability of the nervous system, because the finger activity originates from the muscles, which are innervated by the nerves. When the excitability of the nervous system is too high, a small stimulus may lead to nerve impulses, resulting in involuntary muscle contraction and causing finger twitching. Therefore, the specific situation of finger twitching needs to be diagnosed at the hospital by a professional doctor. The easiest way is to take a blood test to check whether the blood calcium level is normal, so that the cause of finger twitching can be understood through visual judgment.