Too little sleep will reduce the body’s immunity, inducing certain diseases, such as endocrine disorders, easy to catch a cold, neurasthenia, urticaria, allergies, infections, gastrointestinal disorders, gastrointestinal ulcers and tumors, etc., and even trigger the onset of some acute illnesses such as myocardial infarction, cerebral infarction, sudden death and other life-threatening. For the growth and development of children, but also affect the normal growth and development, such as slow growth can occur. Regular and appropriate length, generally 6 to 8 hours a day, infants and young children more than 9 hours of sleep a day, in order to ensure their own good repair and regulation function, to ensure that the body is in a good state of immunity.