The reasons for this may depend on many factors, such as the person’s age, health history, type of TRT used, and how much testosterone is given. It also increases the number of red blood cells, which can make the blood thicker. Testosterone can affect how the heart beats, how blood flows, and how the nervous system controls these actions. In summary, TRT may raise heart rate in some people, but this effect is not the same for everyone. Eating a healthy diet, staying active, avoiding smoking, and managing stress can support heart health while taking TRT. There are steps that can help reduce the risk of side effects. This may include blood tests, blood pressure checks, and heart monitoring. A fast heart rate can happen with other symptoms that may affect health and quality of life. While many people take TRT without major side effects, some report feeling a faster heart rate, also known as tachycardia. This can affect how much of the hormone is active in the body and may have unknown long-term effects on liver and heart function. Also, oral testosterone passes through the liver, which processes the hormone before it reaches the bloodstream. Similar to injections, this may stimulate the heart, increase metabolism, and raise the heart rate in some people. After taking a dose, testosterone can enter the blood quickly, leading to a short-term rise in levels. This happens because testosterone may stimulate the nervous system, increase metabolism, and raise blood pressure slightly. This affects how quickly testosterone enters the bloodstream, how long it stays at certain levels, and how the body responds to it. This may include checking blood pressure, cholesterol levels, heart rhythm, and signs of heart failure. This condition thickens the blood, making it harder for the heart to pump and increasing the risk of blood clots, strokes, and heart attacks. These changes can be mild in healthy people, but they can be more serious in those with heart disease. Testosterone is a hormone that has effects throughout the body, including the cardiovascular system. During treatment, doctors should follow up regularly to check testosterone levels and make sure they stay in the normal range. These symptoms may be caused by changes in how the nervous system reacts to the hormone or by an increased metabolism. A fast heart rate is not one of the most common side effects of TRT, but it can happen. One clinical trial published in The New England Journal of Medicine studied older men with low testosterone levels. To understand the connection between TRT and heart rate, researchers have looked at various types of studies. TRT can possibly increase heart rate by affecting the nervous system, boosting metabolism, or changing how active a person feels. This helps to find out if the therapy is affecting the heart and if any changes in heart rate are happening. It is also important to consider other reasons why heart rate might increase. For those with heart issues or sensitivity to changes in hormones, these ups and downs may be uncomfortable. These differences can also influence the heart, including how fast it beats and whether there are changes in blood pressure or rhythm. These effects are especially important in people with preexisting heart problems. For others, it may be safe if they are carefully monitored and their heart disease is well controlled. Adding testosterone could potentially make these symptoms worse if the heart is forced to work harder. Heart failure is a condition where the heart does not pump blood as well as it should. Clinics and online services now make it easier for men to get testosterone therapy. In addition, the severity of CAD15,17,29–30 and CHF137 correlates with the degree of testosterone deficiency. Although these results are statistically significant, the authors correctly point out the weaknesses of their study which include retrospective study design and lack of randomization, small sample size at extremes of follow‐up, lack of outcome validation by chart review and poor generalizability of the results given that only male veterans with CAD were included in this study. If a transdermal preparation of testosterone is used, a skin reaction at the site of testosterone application is common.146 The clinical implications of this finding remain unknown at this time. However, the authors correctly pointed out that their study was limited by a very small sample size and was therefore meant to be a hypothesis‐generating study. If heart rate changes are linked to TRT, the doctor might adjust the treatment plan. These tests help find causes such as arrhythmias, high blood pressure, or other hidden heart problems. If heart rate or other vital signs change, the dose may be adjusted or additional tests ordered. These symptoms could mean that the heart is working too hard, possibly because of the effects of TRT or another medical issue. However, a consistent or sudden rise in heart rate that causes discomfort should not be ignored. This may be due to how testosterone affects the nervous system, metabolism, and blood flow. A normal resting heart rate for most adults is between 60 and 100 beats per minute (bpm).
