Writer: Jillian Foglesong Stabile, MD, FAAFP, DABOM
Testosterone is a vitally important hormone in the body and a hot topic in health circles. You may hear a lot about the potential risks and symptoms associated with low testosterone, but what about high testosterone? Can high testosterone cause heart problems and other side effects? Here's what you need to know about the relationship between high testosterone and heart problems.
What Is Testosterone?
Testosterone is a steroid hormone that is primarily made in the testicles in men and people assigned male at birth (AMAB), but also in the ovaries of women and people assigned female at birth (AFAB), as well as the adrenal glands. [1, 2]
Testosterone can have a significant role in many parts of your body, including your heart. The relationship between testosterone and heart disease is complex and is also the subject of ongoing investigation.
The Role of Testosterone in the Heart
Testosterone plays a role in many bodily functions. In the cardiovascular system (which is comprised of the heart and blood vessels), testosterone is responsible for increasing red blood cell production. The heart itself is a muscle, and most muscles in the body have receptors that bind male hormones such as testosterone. This means that testosterone may affect how the heart contracts, among other functions. [3]
Decreasing testosterone levels with age are believed to be one of the reasons that men are more likely to develop heart disease than women, but the relationship isn't fully understood.[3]
Both low and high levels of testosterone may play a role in heart disease, which makes this relationship even more complex. Anabolic steroids used by athletes have been associated with high blood pressure, heart attacks, and strokes. Additionally, animal studies have shown that giving animals testosterone can result in an enlarged heart.[3] High-dose testosterone and other androgenic hormones have been associated with increased LDL and decreased HDL cholesterol. However, men who are on testosterone blockers, such as those with prostate cancer, also experience rises in cholesterol.[3]
What Are the Symptoms of High Testosterone?
High testosterone can have several potential symptoms. Some of the potential symptoms of high testosterone include the following [4]:
- Difficulty with erectile function
- Decreased sperm counts
- Shrinking of testicles
- Acne
- Enlarged prostate and difficulty urinating
- Liver problems
- Increased appetite
- Headaches
- Difficulty sleeping
- Predisposition to blood clots
- Increase in muscle mass
- Growth problems in adolescence
- Mood swings and irritability
- Impaired judgment and potentially aggressive behavior
Both men and women with elevated testosterone levels may experience abnormal hair growth and infertility. Women and people AFAB may also have shrinking of the breasts and excessive facial hair growth.
Some symptoms may be linked to both heart disease and high testosterone, such as changes in blood pressure, chest pain, and difficulty breathing. Your healthcare provider can help you determine whether to check your testosterone levels if you have symptoms that may overlap.
Testosterone and Exercise
With its effects on muscle building and red blood cell production, some people look to testosterone for positive effects on their workout. Testosterone can have many effects on exercise capacity and stamina.
But does testosterone increase resting heart rate? The data are mixed regarding this. Some studies have shown a decrease in resting heart rate after treatment, while others have not shown a significant impact. [5,6] Studies have also shown that testosterone replacement therapy, specifically returning testosterone levels to the physiologically normal range, may improve heart rate variability. [5,7]
What Role Does Testosterone Play in Heart Disease?
Likely because of the increased attention on hormone testing and testosterone replacement, there has been increased attention on the effects of this treatment. The relationship between heart disease and testosterone is complex. The studies showing links between the two have been mixed, and additional research is ongoing.
Both low and high levels of testosterone may have effects on the vascular system, including the heart. [8-10] Men with testosterone levels in the lowest quarter of the normal range have up to a 40% increase in 20-year mortality in several population-based studies, though other studies have not found a significant impact. [11]
A 2019 study in the British Medical Journal evaluated data on men who were genetically likely to have elevated testosterone levels to determine whether that was a risk factor for blood clots, heart failure, and heart attacks. This study showed that there was an association between high levels of testosterone naturally produced in the body and an increased risk for heart disease and blood clots. [10]
Studies looking at the effects of testosterone replacement therapy have had mixed results when it comes to heart health. Multiple studies in the early 2010s showed an increased risk of heart disease in men receiving testosterone therapy, resulting in the Food and Drug Administration issuing a safety warning on testosterone therapy in older men. [8-10] On the other hand, a 2023 study in the New England Journal of Medicine found that testosterone replacement therapy did not demonstrate a significant increase in cardiovascular events when compared to placebo. [10] This study looked at hormone replacement, but not the effects of abnormal levels of testosterone in the study population.
Anabolic steroid use by athletes has been associated with an increased risk of coronary artery disease, heart attacks, and sudden cardiac death. [12]
Abnormal levels of testosterone can also increase the risk of other health conditions, such as diabetes and inflammation. These conditions may also increase the risk of heart disease. [13] The complex relationship between testosterone levels and multiple health conditions is another reason why knowing your levels can be important to your health.
How Much Testosterone Is Too Much?
The normal range for testosterone varies by age. This is believed to be related to how the brain and testicular function vary with time. There is a spike in testosterone levels during puberty, and they peak in the late teens to early twenties. [14-16] After age 30, testosterone levels start to decline gradually, usually around 1% per year. [15] After age 80, this level drops much more rapidly. [17] An elevated testosterone level is above the reference range for the patient's age.
Checking testosterone levels is important if you have symptoms or if you are on therapy that can affect your testosterone levels, due to the potential impacts on your heart and other health factors.
When Should Testosterone Be Checked?
Testosterone levels may be important if you have symptoms of an abnormal testosterone level, whether high or low. These symptoms may include [4,18]:
- Excess facial hair
- Acne
- Irregular menstrual periods
- Difficulty getting pregnant
- Voice changes
- Hair loss
- Shrinking of the testicles
- Headaches
- Mood swings
- Irritability
- Difficulty urinating
- Erectile dysfunction
The American Urological Association (AUA) has noted that testosterone therapy may be prescribed to many men without a clear indication for treatment, some of whom did not have labs drawn before starting therapy. Additionally, many people who are on hormone replacement therapy do not have follow-up labs to check on the levels of testosterone after therapy. [19] Since both low and high testosterone levels can have health implications, it is important to have follow-up lab testing drawn at the recommendation of your healthcare provider.
Abnormalities in testosterone levels can impact growth and puberty onset, so children who are having puberty earlier or later than normal may also need to have their testosterone levels checked. [15] People who are on gender affirming hormone replacement therapy may also need to have their levels checked periodically at the recommendation of their healthcare provider. Knowing your levels is important since there are so many potential impacts that testosterone can have on your body and your heart.
Know Your Hormone Levels With Everlywell
Whether testosterone is too low or too high, it can impact your health. The symptoms of abnormal testosterone levels mimic many other conditions, and it can be difficult to know whether this hormone is the source of symptoms. Since abnormal testosterone levels can affect your quality of life, your mood, energy, sexual function, strength, and fertility, it's important to know where your levels stand and whether testosterone levels could be contributing to your symptoms or whether those levels could affect your heart.
Testing your levels is one of the ways you can determine whether testosterone levels, high or low, are causing your symptoms. At Everlywell, we are here to help you on your healthcare journey. We offer a range of lab studies, including tests for hormones and biomarkers. Our Men's Health Test can give you insight into your levels of four important biomarkers, including testosterone. For a more comprehensive look at your overall health, including hormones, consider the Everlywell 360 Full Body Test. Or, if you want to focus solely on this key hormone, the Everlywell Testosterone Test is also available. Getting guidance from a healthcare provider is also important in interpreting these results. We offer virtual men's health appointments as well. Our online platform allows you to meet with one of our credentialed healthcare providers for guidance and advice regarding your lab studies. With Everlywell, you can check your levels and access healthcare on your schedule.