Pediatrics is the branch of medicine dealing with the health and medical care of infants, children, and adolescents from birth up to the age of 21. It is performed by a pediatrician, a child's physician who provides not only medical care for children who are acutely or chronically ill but also preventive health services for healthy children. Pediatrics aims to reduce infant and child rate of deaths, control the spread of infectious disease, promote healthy lifestyles for a long disease-free life and help ease the problems of children and adolescents with chronic conditions. Specifically, pediatricians diagnose and treat conditions such as injuries, infections, genetic variance, congenital defects, cancers, organ diseases and dysfunctions. They also help to manage problems such as developmental delays and disorders, behavioral problems, functional disabilities, social stresses, mental disorders e.g. depression and anxiety disorders. Children have to be treated differently because their bodies are substantially different physiologically from that of an adult. Pediatricians administer vaccinations to children and ensure they meet milestones in growth, behavior, and skills. Pediatrics is divided into 4 main areas: General Pediatrics - hospital-based, covering children from birth to the age of 16; Neonatology - usually based in an intensive care unit looking after premature babies or those with problems at birth; Community Pediatrics - based in the community and focuses on children with developmental, social or behavioral problems and those with a physical disability; Pediatric Cardiology - involves the diagnosis and treatment of children with heart conditions; Allergy and Immunology; Otolaryngology.