Obesity is when a child has too much body fat. Learn more about this condition.
Obsessive-compulsive disorder (OCD) includes thoughts and obsessions (impulses or images) that occur over and over, and that cause a child or teen to feel a great deal of distress.
Obstructive sleep apnea is when a child briefly stops breathing while sleeping. It often occurs because of a blockage in the airway. Read more about this disorder.
An omphalocele is a birth defect in which some of the abdominal organs protrude through an opening in the abdominal muscles in the area of the umbilical cord. A translucent membrane covers the protruding organs.
An optic nerve glioma is is a tumor that grows on the optic nerve (or visual pathway). Learn more about this condition.
Learn more about oral immunotherapy for peanut allergy, which is is when we expose your child to peanut starting at very low doses and slowly increase to a target peanut dose. The goal is to reduce symptoms of an allergic reaction in case your child accidentally eats peanut.
Orbital and ocular tumors are benign (non-cancerous) or malignant (cancerous) tumors that develop in or around the eyes. Learn more about the causes, symptoms and treatments for orbital and ocular tumors in children.
Orthopaedic birth defects include a wide range of conditions affecting a baby’s bones and muscles, tendons and ligaments that connect them. Learn more about the causes, symptoms and treatments for orthopaedic birth defects.
Osteogenesis imperfecta (OI), also known as brittle-bone disease, is a genetic (inherited) disorder characterized by bones that break easily without a specific cause. Learn more about this condition.
Osteosarcoma is cancer of the bone. It’s rare, but it is the most common type of bone cancer children and teens. Learn more about this condition.