Child height: Height refers to the sum of the length of the head, spine and lower limbs. Most children under 3 years of age are not easily measured accurately in the standing position and should be measured in the supine position, which is called length. The measurement in the standing position is called height. The measured value in the standing position is 1-2 cm less than in the supine position. The growth pattern of height (length) is similar to that of weight, with the younger the child, the faster the growth, and two growth peaks occurring during infancy and adolescence. The average length at birth is 50 cm, the first year after birth is the fastest growth, about 25 cm, and about 75 cm at the age of 1 year; the second year the growth rate is slow, about 10-12 cm, and about 87 cm at the age of 2 years; after 2 years the height growth is 6-7 cm per year. is a decrease in growth rate. The growth of height (length) is influenced by genetics, endocrine and intrauterine growth levels, and short-term fluctuations in disease and nutrition do not easily affect the growth of height (length). Child weight: weight is the total weight of organs, systems, and body fluids. Among them, bones, muscles, internal organs, body fat and body fluids are the main components. Weight is the most volatile of the physical growth indicators because of the high variability of body fat and body fluids. Body weight is the easiest indicator of children’s growth and nutritional status. The growth of children’s body weight is not equal, so the evaluation should be based on the changes of individual children’s own weight growth, and should not be evaluated by “formula” calculation, nor should the population average (the so-called “normal value”) be taken as the “standard”. It is not appropriate to use the population average (so-called “normal value”) as a “standard”. When there is no condition to measure weight, the following formula can be used to estimate weight for the convenience of medical staff to calculate the amount of medication and fluids for children. Normal child weight and height estimation formula: (1) Weight: 12 months weight (kg) = 10; 1-12 years weight (kg) = age (years) x 2 + 8; (2) Height: 12 months length (cm) = 75; 2-12 years height (cm) = age (years) x 7 + 75.