When these levels get too high, the blood becomes thicker. These changes are important because they can raise your risk of certain health problems if they are not watched closely. The most important part is regular blood testing and close communication with your healthcare provider. Stopping TRT because of high hemoglobin is sometimes necessary to protect your health. Some people may think a slightly high hemoglobin level is not serious, especially if they feel well on TRT. Older men may have increased sensitivity of hematopoietic (blood-forming) tissue to testosterone. Hematocrit (Hct) is the percentage of blood volume made up of red blood cells. High hematocrit means an elevated red blood cell count. When your blood gets oversaturated with red blood cells relative to white blood cells, platelets, and plasma, it blood gets too thick. Polycythemia develops when you produce too many red blood cells, the oxygen-carrying cells that give blood its crimson hue. In cases where hematocrit levels remain high, therapeutic phlebotomy, a procedure to remove blood from your body, may be recommended. An American study that evaluated the effects of graded doses of testosterone on erythropoiesis found that the percentage of hematocrit started to increase within one month of the start of treatment and continued to increase after three months in a linear dose-dependent manner.9 The study also reported that increases in hematocrit were exaggerated in older men (60–75 years of age) versus young men (19–35 years of age). The study authors analyzed the levels of testosterone and concentration of red blood cells in the blood of 6,670 transmasculine individuals. If you're at high altitude, your body naturally produces more red blood cells to compensate for lower oxygen levels in the air. All three can contribute to secondary polycythemia by depriving your body of oxygen and stimulating the production of extra red blood cells to oxygenate your tissues, says Shatzel. Calculated free testosterone also rose significantly in testosterone-treated men with a similar time course and also reaching a plateau at 3 months (Figure 2). To characterize association between measured quantities (hemoglobin, hematocrit, etc.), we used generalized additive models. The statistical significance of effects was evaluated using Wald tests.To characterize association between measured quantities (hemoglobin, hematocrit, etc.), we used generalized additive models. The enrollment in the trial was halted by the trial’s Data and Safety Monitoring Board due to an increase in cardiovascular events in the testosterone arm (13). Taken together with historical data, these observations provide important leads to the mechanism by which testosterone induces erythrocytosis. We assessed the hormonal and hematologic responses to testosterone administration in a clinical trial in which older men with mobility limitation were randomized to either placebo or testosterone gel daily for 6 months. While not everyone will experience them, recognizing early warning signs helps ensure safe and effective therapy. Because it can be hard to judge severity on your own, any new or unusual symptom should be discussed with your healthcare provider. This is why routine blood testing is essential during TRT. It’s a known risk of taking testosterone for any reason. Without treatment, polycythemia can cause serious and even fatal complications. It’s typically possible to reduce testosterone-induced polycythemia. Polycythemia makes it harder for your heart to circulate blood throughout your body, and it can lead to complications such as high blood pressure or stroke. In addition, patients with posttransplant erythrocytosis, renal dysfunction, and some populations who live at high elevation show evidence of a new EPO/hemoglobin set point (34,43,44). This new equilibrium set point for EPO/hemoglobin has precedent in the observation that men and women have different hemoglobin reference ranges yet similar EPO levels (42).
