Hyperbilirubinemia is a condition in which there is an excess of bilirubin in the bloodstream. Bilirubin is a yellowish compound produced by the breakdown of red blood cells, and the most common cause of hyperbilirubinemia is an increase in red blood cell breakdown. This can be caused by a variety of different conditions, including hemolytic anemia (a condition in which the body produces too many red blood cells), liver disease, certain medications, and some metabolic disorders. When bilirubin levels become too high, it can cause a variety of signs and symptoms such as jaundice (a yellow discoloration of the skin and eyes), itching, dark urine, and fatigue. Hyperbilirubinemia can also lead to serious complications such as kernicterus, a type of brain damage caused by prolonged exposure to high levels of bilirubin. The diagnosis of hyperbilirubinemia is typically made through a physical examination and laboratory tests that measure the levels of bilirubin in the blood. Treatment depends on the underlying cause of the condition, but may include medications, such as phototherapy or exchange transfusions, to reduce the bilirubin levels. In some cases, treatment may also involve lifestyle adjustments such as avoiding certain medications or foods that can increase bilirubin levels. Hyperbilirubinemia is a potentially serious condition, but with prompt diagnosis and treatment, most people experience an improvement in their symptoms and an overall improvement in their health. It is important to speak with a healthcare provider if you are experiencing any symptoms of hyperbilirubinemia.