Cramps, also known as spasms, may be caused by cold stimulation, calcium deficiency, long exercise time and other factors. 1. Cold stimulation: If the elderly are in a place with low room temperature (e.g. winter night, summer air-conditioned house), or the blanket is too thin when sleeping, the foot muscles can be stimulated by the cold and cramps can occur. 2. Calcium deficiency: As the elderly age, the calcium absorption ability is weakened, which can lead to calcium deficiency, resulting in foot cramps, insomnia, back and leg pain and other phenomena in the elderly. 3. Exercise for too long: Older people who exercise with greater intensity and for a longer period of time can also cause foot cramps. In addition, foot cramps can also be caused by foot pressure, etc. It is recommended that patients go to the hospital in time to exclude physiological factors, and then receive treatment as soon as possible.