Hand cramps in summer may be caused by dehydration, hypocalcemia and osteoporosis. 1. Dehydration: Due to the hot temperatures in summer, prolonged outdoor labor, drinking too little water and sweating too much may lead to dehydration, resulting in symptoms such as hand cramps, fatigue, dizziness, nausea and vomiting. 2. Hypocalcemia: Hypocalcemia is a condition in which the level of serum calcium ions is lowered. It is a clinical syndrome caused by hypoparathyroidism, hypomagnesemia, acute pancreatitis, etc. It is mainly manifested by symptoms such as cramps in the hands and feet, muscle twitching, and cardiac arrhythmia. 3. Osteoporosis: Osteoporosis is a systemic bone disease, the onset of which may be related to drug stimulation, estrogen reduction, decreased nutrient absorption, abnormal regulation of bone metabolism, calcium metabolism abnormalities, etc. Patients may experience pain in the lower back or peripheral bones, deformation of the spinal column, fatigue, and cramps in the hands and feet. It is recommended that patients seek timely medical examination to clarify the cause of the disease and then carry out targeted treatment, pay attention to rest in life, avoid strenuous exercise, and at the same time pay attention to monitoring the condition, regular review, and so on.