What are the symptoms of low testosterone?
The symptoms that point most to low testosterone are sexual: less interest in sex, fewer morning erections, and trouble getting or keeping an erection (erectile dysfunction). A study of 3,369 men aged 40 to 79 found that only these three symptoms clustered with low testosterone.
Physical signs, such as loss of body hair and very small testes, point to it even more strongly, according to the Endocrine Society. This guide is part of our starting TRT series.
Many other symptoms get blamed on low testosterone. These include tiredness, low mood, poor focus, poor sleep, weaker muscles and more body fat.
They are real, and they can go along with low levels. But they are also common in men whose testosterone is normal.
The American Urological Association (AUA) calls the symptoms of low testosterone “very non-specific.” Chronic fatigue, stress or depression can cause them too.
So symptoms start the question, and a blood test answers it.
This guide ranks the symptoms by how much they tell you.
It also covers what else can cause them and how common low testosterone is at each age. It can’t tell you whether you have low T. Only testing can.
Which low T symptoms are most specific?
The Endocrine Society sorts symptoms and signs into three groups, from most specific to least:
| Group | Symptoms and signs |
|---|---|
| Specific | Loss of body hair (armpit and pubic), very small testes, incomplete or delayed sexual development |
| Suggestive | Low sex drive and activity, fewer spontaneous erections or erectile dysfunction, breast discomfort or growth, low sperm count or infertility, height loss or low-trauma fractures, hot flushes and sweats |
| Nonspecific | Low energy and motivation, low mood, poor concentration and memory, sleep problems, mild anemia, less muscle and strength, more body fat |
There is one big catch. The guideline says this list comes from men with severe testosterone deficiency. It adds that no surveys of the general population cover the full range of severity.
In middle-aged and older men, symptoms are usually milder. They also get mixed up with the effects of age and other illnesses. Your age, your health, how low and for how long your testosterone has been low, and how sensitive you are to testosterone all shape the picture.
Which sexual symptoms point to low T?
Three stand out in the best population data: poor morning erections, low sexual desire and erectile dysfunction. The chance of having them rose as total testosterone fell below roughly 8 to 13 nmol per liter, which is about 231 to 375 ng/dL. The same was true of being unable to do vigorous activity.
Erectile dysfunction on its own is a weaker clue than many people think.
The AUA pooled 29 studies. Men with ED had only slightly lower testosterone than men without it. The gap was too small to tell the two groups apart.
Even so, the AUA advises clinicians to measure testosterone in men with ED. Low T is one possible cause among several.
Can low testosterone cause tiredness or low mood?
Tiredness and low energy
It can play a part, but tiredness alone rarely means low T. A review of four studies with 4,426 men found fatigue somewhat more common in men with low testosterone.
The AUA says fatigue, especially in the afternoon, may go with low testosterone. But it is non-specific and often has another cause.
In the large European study, fatigue was linked to lower testosterone. On its own, it was not part of the low T pattern. Poor sleep, sleep apnea, depression, anemia, thyroid problems and plain overwork are all more common explanations.
Depression and low mood
The two are linked, but they are not the same thing.
Men with depression are more likely to have low testosterone.
Yet a review of seven studies found no clear difference in depression between men with low and normal testosterone. In a study of 3,987 men aged 71 to 89, men with depression were more likely to have free testosterone in the lowest fifth.
Free testosterone is the small share that isn’t bound to proteins in your blood. That study could not show which came first.
The symptoms overlap a lot.
The National Institute of Mental Health lists fatigue, trouble concentrating, sleep problems, irritability and problems with sexual desire and performance as signs of depression. That is almost the same list as low T. It is why a doctor needs to look at both.
If you feel hopeless or have thoughts of harming yourself, call or text the 988 Suicide and Crisis Lifeline at 988.
What else can cause the same symptoms as low T?
Several common conditions cause symptoms that look like low testosterone. Some of them also lower testosterone itself:
- Sleep apnea: your breathing stops and starts during sleep. Daytime sleepiness, trouble focusing and low libido are all common symptoms. Broken sleep is also linked to both erectile dysfunction and low testosterone.
- Underactive thyroid: this means your thyroid gland makes too little hormone. Fatigue, weight gain and depression are common symptoms.
- Excess weight and type 2 diabetes: obese men are almost five times as likely to have low testosterone. In one small study, a third of men with type 2 diabetes had low free testosterone. In a US community study, waist size was the biggest factor linked to low testosterone.
- Medicines: opioids and glucocorticoids (steroid medicines such as prednisone) can lower testosterone, and the effect may be reversible.
That is why prescribers ask about sleep, weight, mood and medicines before treating low testosterone. The AUA also suggests a testosterone test for men with unexplained anemia, bone loss, diabetes, long-term opioid or steroid use, or infertility, even without typical symptoms. Our guide to how low T is diagnosed explains how they look for the cause.
Can low T cause weight gain, breast changes or bone loss?
These physical changes are real parts of the picture. Each one needs care in how you read it.
Weight, muscle and body fat
The link runs both ways. Low testosterone goes with less muscle and more body fat. Extra weight also lowers testosterone.
In the European Male Ageing Study, men with a BMI of 30 or more had clearly lower total and free testosterone than men with a BMI under 25. The pattern suggested the problem began in the brain’s signals, not the testes. That is one reason prescribers look at weight before deciding what is cause and what is effect.
Breast tenderness or growth
Breast discomfort or growth of breast tissue (gynecomastia) is one of the Endocrine Society’s “suggestive” signs. The AUA advises measuring estradiol, a form of estrogen, in men with breast symptoms before any treatment.
It also reminds clinicians that any breast enlargement raises the possibility of cancer. A new breast lump always needs to be checked by a clinician.
Bone loss, height loss and fractures
Low bone density, height loss and fractures from minor falls are also suggestive signs. The AUA suggests testing testosterone in men with unexplained bone loss.
In the Testosterone Trials, a year of treatment raised bone density and estimated bone strength in older men with low testosterone. The trial was too small to show whether it prevents fractures.
Hot flushes and sweats
Hot flushes and sweats are also listed as suggestive signs. We found no study that says how often they happen in typical adult men with low levels.
How common is low testosterone by age?
It is more common than the symptoms suggest, but less common than advertising suggests. A lot depends on whether you count only a low number or a low number plus symptoms:
| Study | Who | Finding |
|---|---|---|
| Boston Area Community Health study | 1,475 men aged 30 to 79 | Low testosterone plus symptoms in 5.6%; 3.1 to 7.0% under 70, rising to 18.4% in men in their 70s |
| HIM study | Men 45+ visiting primary care | Total testosterone below 300 ng/dL in 38.7%, with or without symptoms |
| Baltimore Longitudinal Study | 890 men followed over time | Low levels in about 20% of men over 60, 30% over 70 and 50% over 80 |
Two things stand out.
First, many men with low levels feel fine. In the Boston study, 47.6% of men aged 50 and over with low testosterone had no symptoms.
Second, age is not the whole story. Men over 40 who reported very good health showed no age-related drop at all. Obesity went with lower levels.
Are low T symptoms different in your 30s, 40s and 50s?
The symptoms are the same at any age. What changes is how likely they are to mean low testosterone, and what else might explain them. We found no solid source that lists symptoms “by decade,” so be wary of pages that do.
- In your 30s: low testosterone is less common. Tiredness, low mood and low libido more often come from sleep, stress, weight or depression. Specific signs, such as loss of body hair or a change in testis size, deserve prompt attention at any age.
- In your 40s and 50s: low levels become more common. They often come with weight gain, diabetes or poor sleep, which can lower testosterone themselves.
- In your 60s and beyond: low levels are common, but so are other health problems with similar symptoms. The Endocrine Society notes that vague symptoms and low testosterone often show up together in older men without a clear cause-and-effect link.
Can you have symptoms with a normal testosterone level?
Yes, for two reasons. First, the symptoms may have another cause, as above.
Second, total testosterone doesn’t always tell the full story. In a European study of 3,334 men, those with normal total testosterone but low free testosterone reported more sexual and physical symptoms. Our page on free testosterone explains when it is checked.
It also works the other way: a single low result can mislead. The Endocrine Society notes that about 30% of men with a low first result have a normal level when retested. That is why diagnosis needs two morning tests.
Can a quiz or questionnaire tell if you have low T?
It can tell you whether to get tested. It can’t tell you whether you have low testosterone.
The ADAM questionnaire caught 88% of men with low bioavailable testosterone (the part your body can use). But it was only 60% specific, so many men who score positive have normal levels. In a follow-up group, 37% of men who screened positive but had clearly normal levels showed some signs of low mood.
The AUA doesn’t recommend questionnaires for deciding who should be treated. Questionnaires disagree on which symptoms matter, and testosterone matches up poorly with most of their questions.
How do you find out if your symptoms are low testosterone?
With blood tests. The Endocrine Society recommends diagnosing low testosterone only when your symptoms fit and a fasting morning test is low, confirmed by a repeat. The AUA treats a total testosterone below 300 ng/dL, measured twice in the early morning, as a reasonable cut-off.
Before you go, write down your symptoms. Note what they are, when they started and how much they bother you on a 0 to 10 scale. Add any other conditions and medicines.
Our guide to preparing for a TRT appointment has a full list.
If you start treatment, the blood test timing tool helps you book the right time of day.
What happens to low T symptoms with treatment?
Some improve, and some don’t.
The Testosterone Trials followed 790 men aged 65 and older with low testosterone and symptoms. A year of treatment improved sexual activity, desire and erectile function. It slightly improved mood, but not vitality.
A review of 27 trials found a small drop in depressive symptoms. In men with unexplained anemia, hemoglobin (the part of red blood cells that carries oxygen) rose more often on testosterone than on placebo.
Treatment also has risks and trade-offs, including effects on fertility. Talk with your prescriber about what to expect before you decide to go ahead.
What should you ask your prescriber about your symptoms?
- Could my symptoms have another cause, such as sleep, mood, weight or a medicine?
- Should my testosterone be tested, and should it be in the morning and fasting?
- Do I need free testosterone or other tests too?
- If my levels are normal, what else should we look at?
- If they’re low, what’s likely causing it, and is it reversible?