Pediatrics is the branch of medicine focused on the health and medical care of babies, children, and teenagers. A doctor who specializes in pediatrics is called a pediatrician. While your family doctor might treat patients of all ages, a pediatrician has special training in how young bodies grow, develop, and fight off illness differently than adult bodies.

Pediatricians treat sick kids and also track growth patterns to make sure children are developing properly, give vaccinations to prevent diseases, and help parents understand what's normal at each stage of childhood. They know, for instance, that a fever that might worry parents is often just a sign that a child's immune system is doing its job, or that certain rashes are harmless even though they look alarming.

Pediatrics became its own medical specialty in the 1800s when doctors realized that children aren't just small adults: their bodies work differently, they need different medication doses, and they face unique health challenges as they grow. A pediatrician needs to understand not just medicine, but also how to comfort a scared five-year-old or communicate with a stubborn teenager.