The common reasons for cramps in the hands and feet when you are tired of doing work are the following: First, due to a huge workload that exceeds the body’s load capacity, resulting in muscle damage, strain, and muscle dysfunction in the limbs, leading to cramping symptoms. Second, due to excessive exercise, too long resulting in the accumulation of metabolites in the muscle, such as lactic acid, creatine stimulates muscle dysfunction, resulting in cramping symptoms. Third, the body has basic diseases, such as calcium deficiency or renal insufficiency, which can easily lead to a lack of the corresponding calcium ions and muscle dysfunction cramps. Fourth, if you work more in hot conditions, it will lead to more sweating and relative dehydration, resulting in water and sodium metabolism disorders and corresponding muscle dysfunction leading to cramps.