It is important to note that you could be having a heart attack without feeling discomfort in your chest, as is common in women. A sudden feeling of fatigue for no reason could be a sign that a heart attack is incoming. The heart has to work harder as arteries begin to close, and can make simple tasks feel exhausting. This can result sleeping longer hours at night or feeling like you need to take multiple naps during the day.
Polycythemia is an increased number of red blood cells in the blood. In polycythemia, the levels of hemoglobin (Hgb), hematocrit (Hct), or the red blood cell (RBC) count may be elevated when measured in the complete blood count (CBC), as compared to normal. Hemoglobin levels greater than 16.5 g/dL (grams per deciliter) in women and greater than 18.5 g/dL in men suggest polycythemia.
Polycythemia vera, or PV, is a rare blood cancer in which the body makes too many blood cells. PV is a chronic, progressive disease.