There are more reasons for shaking legs, which may be cold weather, calcium deficiency and shaking leg syndrome. 1. Cold weather: when the weather is cold, the capillaries of the whole body will contract, and also increase the heat of the body through muscle contraction, so when the weather is cold, there will be shivering, and some of them will be shaking legs. 2. Calcium deficiency: Calcium is an indispensable trace element in the body, and if it is lacking in calcium, the excitability of the nerves will be abnormal, so there will be cramps or convulsions, which will also be manifested as leg shaking. 3. Shaking leg syndrome: Shaking leg syndrome is related to abnormal dopamine metabolism and iron deficiency, and is also called restless leg syndrome, which mainly manifests as unstoppable shaking of the legs, accompanied by strong pain, burning and other discomforts, and usually occurs at night. If the symptoms are not relieved, or accompanied by other symptoms, you should go to the hospital in a timely manner, to identify the cause and give targeted treatment.