Hyperviscosity syndrome is a serious condition caused by an increase in the viscosity of the blood, which in turn is caused by increased circulating serum immunoglobulins and can be seen in diseases, such as immunoglobulin myeloma (plasma cells cancer), Waldenström macroglobulinemia and multiple myeloma. But hyperviscosity syndrome can also arise from increased cellular blood components (white or red blood cells) in hyperproliferative states such as the leukemias, polycythemia, and the myeloproliferative disorders. Symptoms of hyperviscosity syndrome include spontaneous bleeding from mucous membranes, visual disturbances due to retinopathy, and neurologic symptoms ranging from headache and vertigo to seizures and coma. Cardiopulmonary symptoms such as shortness of breath, hypoxemia, acute respiratory failure, and hypotension also result from this sludging of blood and decreased microvascular circulation.
Serum viscosity in healthy persons ranges from 1.4 and 1.8 centipoises. To have symptoms from hyperviscocity syndrome, serum viscosity is usually greater than 5 centipoises. To decrease viscosity, plasmapheresis can be applied in patients with myeloma. During a leukemic or polycythemic crisis, leukapheresis or phlebotomy can be used.