Sleeping feet keep moving for the following common reasons: 1, the patient has hypocalcemia, the patient due to severe osteoporosis, calcium loss, reduced serum calcium ion concentration, will cause increased neuromuscular excitability, thus during sleep will show symptoms of foot cramps. 2, the patient goes to sleep, the main brain cells rest, while the childish brain cells are active, will produce dreams, the patient will have involuntary activity, especially foot activity, when the patient is not awake and unaware of the leg activity. These two conditions are common causes of foot activity during sleep, and usually prompt treatment and diagnosis will not affect the patient’s daily life.