Pediatrics, branch of medicine, that comprises the care and treatment of the diseases of childhood and the study of normal growth. Pediatrics became a specialty in the 20th century. In the 1980s some pediatricians began a subspecialty called adolescent medicine, which deals with the special medical and emotional needs of persons between the ages of approximately 12 and 20 years.

Pediatricians are trained to recognize congenital defects (Birth Defects) and to treat them when possible. One important treatable class of these conditions is congenital heart malformations; surgical correction of these defects has become increasingly successful. Other congenital illnesses that must be diagnosed and treated soon after birth are phenylketonuria and congenital hypothyroidism (Cretinism). Pediatricians must also handle a number of infectious diseases that are most often seen in childhood. These include recurrent ear infections such as otitis media (Ear), mumps, measles, whooping cough, poliomyelitis, and croup. Many of these diseases can be prevented by immunization, which is the responsibility of the pediatrician.

Pediatricians also monitor the normal growth and development of a child according to important motor and intellectual milestones. Recognition of developmental lags may point to lack of proper nutrition, poisoning with environmental substances such as lead, or hyperactivity. In addition, pediatricians must be alert for disorders that usually first become apparent in childhood, such as allergy, immune deficiency diseases (Immune System), and epilepsy.