Physical examination in a patient with polycythemia. General findings from the elevated red cell mass include plethora of skin and conjunctiva, dilated/engaged retinal vessel, and hypertension (remember: cardiac output = mean arterial pressure/total peripheral resistance; increased Hct causes increased viscosity which in turn elevates the peripheral resistance, causing an increased mean arterial pressure to maintain cardiac output). Physical findings associated with individual causes of polycythemia include heart murmur, abnormal heart sounds, signs of heart failure and clubbing in patients with left-to-right shunt and cyanotic heart disease; splenomegaly and signs of scratching (from aquagenic pruritis) in polycythemia vera; renal artery bruit in renal artery stenosis; and abdominal findings associated with intraabdominal tumors. Low arterial oxygen saturation may be found in causes associated with hypoxic cardiopulmonary disease.
