10 signs and symptoms of low testosterone

Reviewed by Chimene Richa, MD, 

Written by Michael Martin 

Reviewed by Chimene Richa, MD, 

Written by Michael Martin 

last updated: Jan 14, 2022

4 min read

Testosterone gets a bad rap for being associated with aggression, ego, and brute force—but it does so much more. You probably know that testosterone is responsible for the male body's development at puberty, but the hormone plays an important role in health at every age. And when your levels of testosterone diminish, it can cause several symptoms that reduce your quality of life. The good news is you don't have to live with it. Here's how to recognize and treat it.

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What is low testosterone?

Low testosterone (also known as hypogonadism or low T) is an abnormally low level of testosterone in the blood. 

The testicles and adrenal glands produce testosterone in males. It's an androgen, or male sex hormone, which is present from birth and is what makes a fetus male. During puberty, levels of testosterone surge, producing secondary sexual characteristics like muscle growth, body hair, and sperm production. And testosterone plays an essential role in people’s health throughout life, regulating libido, erectile function, sperm production, bone density, muscle mass, mood stability, and more (Nassar, 2022).  

Testosterone levels drop naturally with age, beginning in your 30s and 40s. However, aside from aging, there are many other causes of decreased testosterone levels. They include obesity, sleep problems like sleep apnea, chronic diseases, certain types of infections (like HIV), and some drugs (including opioids and steroids) (Sizar, 2021).

Diagnosing low testosterone

The likelihood of having low testosterone increases with age. Your healthcare provider can check your testosterone levels with a blood test.

As a general rule of thumb, normal testosterone levels are between 300 and 1,000 nanograms per deciliter (ng/dL). However, testosterone levels vary significantly throughout the day. They're highest in the morning, and they change from one day to the next. That's why providers usually require two early-morning testosterone levels (usually between 8 a.m. and 10 a.m.) on separate days before diagnosing someone with low T. 

10 signs of low testosterone

Testosterone affects a wide array of bodily functions, so low levels can have seemingly unrelated signs and symptoms. 

1. Low sex drive

Sex drive (or libido) is complicated and can be affected by many physical, mental, and social factors. It can vary from person to person and day to day—sex drive can also go down as we age. But a decline in sexual desire can be a sign of low testosterone. But it's not universal as some men maintain a normal sex drive despite low T, proving that sex drive is more complex than one hormone can control (Rizk, 2017; Shigehara, 2021). 

2. Erectile dysfunction 

Erectile dysfunction (ED) can manifest as fewer spontaneous erections, difficulty getting erections during sexual activity, or fewer morning erections. Essentially, it's when you cannot get or maintain an erection long enough to have a satisfying sex life. Many conditions can cause ED, including low testosterone levels (Rizk, 2017).

3. Fatigue

Sleep disturbances, like sleep apnea, may lead to low testosterone levels. This may occur because most of your testosterone gets produced at night while you sleep. Some studies suggest that poor sleep quality can lead to low testosterone levels, although the data is conflicting. Although the relationship between sleep and testosterone is not clear, people with low T often complain of fatigue and low energy levels (Liu, 2019).

4. Decreased lean muscle mass

Testosterone contributes to muscle building, so muscle mass can decline when your T levels drop (Nassar, 2022).

5. Increased body fat

People with low testosterone levels may notice more body fat. This can lead to obesity or gynecomastia, the development of breast tissue in men (Nassar, 2022).

6. Reduced bone density

Low testosterone can lead to weaker bones. Symptoms can include back pain or a loss of height, but often reduced bone density develops silently until a bump or fall causes bones to break. Your healthcare provider can assess your bone health with a bone mineral density (BMD) test (Snyder, 2017).

7. Hair loss

Hair loss due to low testosterone levels usually involves face and body hair. This is different from most cases of hair loss you know. In adult men, male pattern baldness is usually an inherited condition due to dihydrotestosterone (DHT), a byproduct of testosterone, affecting hair follicles on the scalp and causing hair loss (Nassar, 2022). 

8. Low sperm count

Testosterone plays a role in sperm production, so it is not surprising that low levels can reduce your sperm count (Nassar, 2022).

9. Anemia

Testosterone helps your body make red blood cells, a process called erythropoiesis. Low A decline in testosterone can cause a reduction in the number of red blood cells, also known as anemia (Nassar, 2022). 

10. Mood changes

Some mood changes experienced by people with low testosterone include irritability, fatigue, a chronic low mood, feelings of hopelessness, or lack of enjoyment of activities you previously found pleasurable. Studies suggest that low testosterone levels may contribute to depression (Chen, 2020). 

Individuals may experience all, some, or none of these symptoms. You need to measure your testosterone levels via blood testing for a definitive diagnosis.

Treatment for low testosterone

If you suspect you might have a low testosterone level, it's a good idea to seek medical advice from a healthcare provider who can order tests to get a complete picture of what's going on. You might have low testosterone, or it could be another health problem that can be treated and resolved.

If you have low levels of testosterone, your healthcare provider might recommend TRT, or testosterone replacement therapy, an FDA-approved way to increase testosterone. Testosterone therapy comes in several forms, including (Bhasin, 2018):

Before starting any testosterone therapy, talk to your healthcare provider. The symptoms of low testosterone can mimic other conditions, and it is challenging to determine their true cause on your own.


If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.

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  • Chen, Z., Shen, X., Tian, K., Liu, Y., Xiong, S., Yu, Q., et al. (2020). Bioavailable testosterone is associated with symptoms of depression in adult men. The Journal of International Medical Research , 48(8), 300060520941715. doi: 10.1177/0300060520941715. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/32762464

  • Liu, P. Y. (2019). A clinical perspective of sleep and andrological health: assessment, treatment considerations, and future research. The Journal of Clinical Endocrinology and Metabolism , 104 (10), 4398–4417. doi: 10.1210/jc.2019-00683. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/31042277

  • Liu, T. C., Lin, C. H., Huang, C. Y., Ivy, J. L., & Kuo, C. H. (2013). Effect of acute DHEA administration on free testosterone in middle-aged and young men following high-intensity interval training. European Journal of Applied Physiology, 113 (7), 1783–1792. doi: 10.1007/s00421-013-2607-x. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/31042277

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  • Rizk, P. J., Kohn, T. P., Pastuszak, A. W., & Khera, M. (2017). Testosterone therapy improves erectile function and libido in hypogonadal men. Current Opinion in Urology , 27 (6), 511–515. Doi: 10.1097/MOU.0000000000000442. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5649360/

  • Shigehara, K., Kato, Y., Iijima, M., Kawaguchi, S., Nohara, T., Izumi, K., et al. (2021). Risk factors affecting decreased libido among middle-aged to elderly men; nocturnal voiding is an independent risk factor of decreased libido. Sexual Medicine , 9 (5), 100426. doi: 10.1016/j.esxm.2021.100426. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8498958/

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  • Snyder, P. J., Kopperdahl, D. L., Stephens-Shields, A. J., Ellenberg, S. S., Cauley, J. A., Ensrud, K. E., et al. (2017). Effect of testosterone treatment on volumetric bone density and strength in older men with low testosterone: a controlled clinical trial. JAMA Internal Medicine , 177 (4), 471–479. doi: 10.1001/jamainternmed.2016.9539. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5433755/

How we reviewed this article

Every article on Health Guide goes through rigorous fact-checking by our team of medical reviewers. Our reviewers are trained medical professionals who ensure each article contains the most up-to-date information, and that medical details have been correctly interpreted by the writer.

Current version

January 14, 2022

Written by

Michael Martin

Fact checked by

Chimene Richa, MD

About the medical reviewer

Dr. Richa is a board-certified Ophthalmologist and medical writer for Ro.