A pediatrician is a doctor trained and educated in diagnosing and treating childhood conditions and illness. These conditions and illness may range from minor to serious diseases. They are trained in managing the mental, physical and behavioral health issues in children from birth until the age of 18. Duties and responsibilities of pediatrician involve conducting medical examinations, establishing treatment plans, developing diagnoses, communicating with caregivers and parents, providing referrals to specialists, and maintaining patient records. They also provide immunizations according to school or medical guidelines.