There are several causes of limb pain and weakness: first, the most common disease is the cold, whether it is a bacterial cold, or a viral cold, there will be limb pain and weakness at the beginning, because bacteria, viruses into the body, the production of antigen antibody immune complex reaction and trigger limb pain; second, the previous day too much exercise or exercise the wrong way, resulting in excessive accumulation of lactic acid in the body, or even Third, common endocrinopathies such as periodic hypokalemia can also cause weakness and pain in the extremities; fourth, such as trauma-related diseases or heat stroke resulting in heat cramps, heat exhaustion, and pyrexia, can also cause pain and weakness in the extremities.