The causes of newborns always waking up from sleep are generally the startle reflex and insufficient calcium intake in the body, as follows: 1, startle reflex: the startle reflex is one of the instincts of newborns, which is caused by the child’s sudden noise or bright light stimulation, which will immediately appear with arms straightened, fingers opened, back arched, head tilted back, legs straightened, arms hugging each other, and sometimes the symptoms of crying out loud, with the child’s 2. Insufficient calcium intake in the body: If the baby is not supplemented with vitamin D in time after half a month of life, it will lead to insufficient calcium intake in the body, and due to the lack of calcium in the body, it will lead to increased neuroexcitability and symptoms such as difficulty falling asleep at night, sleeplessness, easy to wake up, crying, night sweats, etc. After parents consult the doctor and supplement vitamin D, the symptoms will After parents consult a doctor and take vitamin D supplements, the symptoms will disappear slowly.