Porphyria is a condition that affects how heme is made and broken down by the
body. Heme is the part of hemoglobin that carries oxygen to the cells of the
What is going on in the body?
Hemoglobin is the main oxygen-carrying component of blood. Porphyrins are
compounds in the body that affect the way hemoglobin is made, stored, and used.
A person with porphyria makes and excretes excessive amounts of porphyrins.
This often causes abnormally high levels of heme in the blood.
There are several kinds of porphyria. Porphyrias are classified by where in the
body the excess porphyrins are made. They include:
erythropoietic, with extra production in the bone marrow
hepatic, with extra production in the liver
erythrohepatic, with extra production in the bone marrow and liver
What are the causes and risks of the disease?
Most cases of porphyria are caused by genetic disorders. Some cases are caused
by toxic substances, such as ingestion or exposure to lead. Menstruation may increase symptoms in women.