PNH diagnosis often involves a combination of clinical evaluation, laboratory tests, and histological analysis. A key diagnostic tool is flow cytometry, which can identify the absence of GPI-anchored proteins on the surface of blood cells. Bone marrow examination may also be performed to assess the degree of bone marrow failure and to rule out other hematological conditions. Additionally, tests for hemoglobinuria (presence of hemoglobin in the urine) and elevated levels of lactate dehydrogenase (LDH) are indicative of hemolysis.
