PRESENT-DAY students are usually taught that Gaisböck's syndrome is a coincidence of polycythemia vera and hypertension. However, as one follows patients with persistently elevated hematocrit values, it becomes apparent that Gaisböck may have been describing a disorder distinct from polycythemia vera. This is important since patients who have had neither an elevated total red blood cell volume, nor polycythemia vera, have been treated by phlebotomy and radioactive phosphorus. This error in diagnosis and treatment is more common than is realized.
Although he recognized increase in the erythrocyte count due to plasma loss, and forms of physiologic polycythemia, Gaisböck1 regarded his polycythemia hypertonica as a true polycythemia. He regarded the presence of hypertension as the most important manifestation separating his syndrome from the Vaquez type of true polycythemia. Since hypertension is common in polycythemia vera 2 he undoubtedly included some cases in his group with polycythemia hypertonica. However, since he