Human growth and development can be expressed in terms of two “ages”, namely the chronological age (calendar age) and the biological age (bone age). Bone age is short for skeletal age and is determined with the help of a specific image of the bone in an X-ray camera. In order to find out the bone age of a person, it is usual to take an X-ray of the wrist of the person’s left hand, through which the doctor observes the degree of development of the metacarpal phalanges, carpal bones and the ossification centers of the lower radius and ulna of the left hand to determine the bone age. We can analyze the following six points: What is the significance of measuring bone age? What are the methods of measuring bone age? What are the diseases associated with abnormal bone age? Why is skeletal age a predictor of adult height? What are the causes of short height in children? What are the methods for children to grow taller? What is the significance of measuring bone age? The development of human bones is basically similar, with each bone developing in a continuous and phased manner. Bones at different stages have different morphological characteristics, therefore, bone age assessment can more accurately reflect the level of growth and maturity of an individual. It can not only determine the biological age of a child, but also provide an early understanding of the growth potential of a child and the trend of sexual maturity: the adult height of a child can also be predicted through bone age, and the determination of bone age is also very helpful for the diagnosis of some pediatric endocrine diseases. What are the methods of measuring bone age? The most commonly used methods are the G-P atlas and the TW2 (TW3) method; the prediction of adult height includes the B-P method, the RWT method, the TW2 method, etc. What are the diseases associated with abnormal bone age? The difference between biological age (bone age)-life age is said to be normal development if it is within ±1 year. If the difference between biological age (bone age) and life age is >1 year, it is called premature development (abbreviation: precocious). Difference between biological age (bone age) and life age