Tic is actually caused by muscle spasm, which is a kind of spontaneous muscle tetanic contraction. The main part of the cramp occurs in the calf and toe muscles. There is a pain when surfing cramps, especially in the middle night cramps tend to wake up people, and this pain will keep for a long time, and affect sleep as well. There are many reasons can cause tic, such as calcium deficiency, improper sleeping posture.
1, The external cold environment stimulation, such as low temperature in winter night, sleep to cover the quilt or thin legs to be exposed outside.
2, Fatigue, rest too little or rest too much lead to the accumulation of local acid metabolites, can cause muscle cramps. Such as walking or exercise time is too long, so that the lower limb fatigue or lack of sleep, can make the accumulation of lactic acid; sleep rest too long, slow blood circulation, so that carbon dioxide accumulation.
3, The elderly women with osteoporosis, estrogen decline, will make the blood calcium level is too low, muscle stress increase, and often spasm.
4, The sleeping posture is not good, such as long time supine, make the quilt in the foot, or the foot long time prone, arrived in bed, forcing some leg muscles for a long time in the absolute state of relaxation, caused by passive muscle contracture.