This test looks for substances called porphyrins in your urine. If high levels are present, you may have a disease that affects the way the hemoglobin in your blood works.

This test looks for P. jirovecii fungus in your lung tissue or in fluid from a lung. This fungus causes pneumocystis pneumonia.

This test measures the number of platelet cells in your blood. It can give your healthcare provider valuable information about how well your blood clots to stop bleeding, how well your bone marrow is working, and diseases that affect your platelet count.

This test looks for platelet antibodies in your blood to find out the cause of a low platelet count.

This test looks for Plasmodium parasites in your blood. The parasites cause malaria, a serious disease that can be fatal if left untreated.

This test checks newborns for PKU, a condition that can cause brain damage and severe intellectual disability if untreated.

This blood test checks the level of phosphorus in your body.

This test checks the level of the seizure medicine phenytoin (Dilantin) in your blood.

This test measures the amount of the medicine phenobarbital in your blood. Phenobarbital is used to treat epilepsy.

This test checks for a current or past infection with the virus that causes fifth disease in children.