Altogether there are seven main types of porphyria, four are acute porphyrias. Most of the others affect only the skin. All seven types are described below. They are called porphyrias because they cause accumulation of chemicals called porphyrins (purple-red pigments named from the Greek for purple) or the simpler chemicals that are used up by the body to make porphyrins. When porphyrins accumulate in the skin, it becomes very sensitive to sunlight and this causes the skin symptoms of porphyria. Accumulation of the simpler chemicals in the liver leads to acute attacks of porphyria. Porphyrins are important in the body because they combine with iron to form haem, a red pigment which has the vital function of enabling the body's cells to use oxygen.
The acute porphyrias are metabolic disorders that affect biochemical processes. They do not cause blood disease or liver disease. There is more information on these on the "acute poprhyrias" page
It is important for you to find out which type of porphyria you have because the inherited abnormality and symptoms are different in each one.