Quick answer: Knowing when to get testosterone checked starts with recognizing the signs. The most common signs of low testosterone in men are persistent fatigue, loss of muscle mass, lower sex drive, mood changes, poor sleep, weight gain around the belly, and trouble focusing. These symptoms overlap with many other health conditions, so low testosterone can only be confirmed with blood tests and an evaluation by a healthcare provider.
What Is Low Testosterone, and Why Get It Checked?
Low testosterone, also called testosterone deficiency or male hypogonadism, happens when the body doesn’t produce enough testosterone. The cause can start in the testicles (primary hypogonadism) or in the pituitary gland or hypothalamus, the parts of the brain that signal the testicles to make testosterone (secondary hypogonadism). Levels also decline gradually with age.
The American Urological Association considers a total testosterone level below 300 ng/dL a reasonable cutoff for diagnosing low testosterone, and a diagnosis requires both low levels and symptoms or signs (Mulhall et al., 2018). When both are present, a provider may discuss whether testosterone replacement therapy (TRT) is appropriate.
Sign 1: Persistent Fatigue
Ongoing tiredness that doesn’t improve with rest is one of the most common complaints in men with low testosterone (Mulhall et al., 2018). Testosterone supports energy in several ways:
- Muscle and stamina: Lower testosterone makes it harder to maintain muscle, so everyday physical activity takes more effort.
- Red blood cell production: Low testosterone is linked to anemia, which reduces oxygen delivery and energy (Mulhall et al., 2018).
- Sleep and mood: Low testosterone is linked to poorer sleep and low mood, both of which drain daytime energy (see Signs 4 and 5).
Fatigue is a non-specific symptom, though. It can also come from chronic stress, depression, thyroid problems, or sleep disorders (Mulhall et al., 2018), which is why testing matters. If tiredness persists even with good rest, it’s a good reason to get your testosterone checked.
Sign 2: Losing Muscle Mass Despite Exercise
If you’re training consistently but losing size or strength, low testosterone may be a factor. Testosterone signals the body to build muscle after exercise, and when levels are low, that balance shifts toward breakdown.
- Slower protein synthesis: Muscle cells receive a weaker signal to build new protein.
- Faster protein breakdown: Muscle tissue is broken down more readily, making recovery harder.
- Reduced muscle repair: Testosterone helps activate satellite cells, which repair and grow muscle fibers after a workout. Low levels blunt this response.
- Poorer recovery: Fatigue and lower energy reduce workout intensity and slow recovery between sessions.
In men with confirmed testosterone deficiency, treatment may improve lean body mass (Mulhall et al., 2018).
Sign 3: Lower Sex Drive
A drop in libido is one of the most specific signs of low testosterone, and one many men don’t talk about. Testosterone is a key driver of sexual desire, so when levels fall, interest in sex often falls with it.
- Reduced desire: The most consistent sexual symptom of low testosterone.
- Fewer morning or spontaneous erections: These depend partly on healthy testosterone levels.
- Erectile dysfunction: Low testosterone can contribute to erection problems, but it’s rarely the only cause. Conditions like diabetes and obesity often play a role and make the link hard to separate (Mulhall et al., 2018).
A noticeable drop in desire is one of the clearest signals to get testosterone checked.
Sign 4: Mood Changes and Irritability
Low testosterone has been linked to irritability, low mood, and depressive symptoms. Testosterone acts on the brain, and changes in levels can affect how you feel day to day (Hauger et al., 2022). Men diagnosed with depression are also more likely to have low testosterone (Mulhall et al., 2018).
Mood-related signs may include:
- Irritability or a shorter temper
- Feeling down, flat, or anxious
- Low motivation or loss of drive
- Reduced sense of well-being
These symptoms can also point to depression or chronic stress on their own, so they’re worth discussing with a provider either way.
Sign 5: Poor Sleep Quality
Testosterone and sleep affect each other. Short or disrupted sleep is associated with lower testosterone in the morning, in the afternoon, and over 24 hours (Liu & Reddy, 2022).
Obstructive sleep apnea is also associated with lower testosterone, even after accounting for age and weight (Liu & Reddy, 2022). High-dose testosterone therapy can bring on sleep apnea, although physiologic dosing may not, and the effect may be temporary (Liu & Reddy, 2022). That’s one reason providers screen for sleep problems before starting treatment.
Sign 6: Weight Gain, Especially Around the Belly
Low testosterone can make it harder to maintain a healthy weight, and excess weight can lower testosterone further.
- Less muscle: Low testosterone makes it harder to maintain muscle (see Sign 2), which can make weight management more difficult.
- More belly fat: Low testosterone is associated with fat building up around the abdomen (Cohen, 1999).
- A reinforcing cycle: Fat tissue contains aromatase, an enzyme that converts testosterone into estrogen. As body fat increases, more testosterone is converted, which lowers testosterone further and encourages more belly fat storage (Cohen, 1999).
Losing excess weight is one of the most effective lifestyle changes for supporting healthy testosterone levels.
Sign 7: Trouble Focusing and Low Motivation
Some men with low testosterone describe “brain fog”: slower thinking, trouble concentrating, forgetfulness, or needing more willpower to get through demanding tasks. Decreased focus is one of the symptoms clinicians look for when evaluating low testosterone.
However, these symptoms may come from chronic stress, fatigue, or depression rather than low testosterone. The evidence is also inconclusive on whether testosterone therapy improves cognitive function (Mulhall et al., 2018). A full evaluation helps identify what’s actually driving your symptoms.
Other Signs You Should Get Testosterone Checked
Less common signs include reduced body or facial hair, hot flashes, breast tenderness or enlargement, smaller or softer testicles, and reduced bone density, which raises fracture risk over time.
When to Get Your Testosterone Checked and How It’s Diagnosed
The best time to get testosterone checked is early in the morning, when levels peak (Mulhall et al., 2018). Low testosterone is diagnosed using a combination of symptoms and blood tests. A typical evaluation includes:
- A review of your symptoms and medical history, including medications, sleep, and weight changes.
- Two early-morning blood tests on separate days. Testosterone peaks in the morning and fluctuates from day to day, so a single test isn’t enough (Mulhall et al., 2018).
- Additional labs, such as luteinizing hormone (LH) and, in some cases, prolactin, to help identify the underlying cause (Mulhall et al., 2018).
Get Your Testosterone Checked at Androgenix
If you’re dealing with these signs or have questions about testosterone deficiency, a proper evaluation can help identify the right approach. Androgenix provides personalized hormone health services, including testosterone testing and hormone optimization support.
Learn more about:
- Hormone Optimization
- 15 Signs of Low Testosterone in Men
- Comprehensive Hormone Testing
- Recommended Blood Tests for Men With Fatigue, Low Libido, and Brain Fog
FAQs: When to Get Testosterone Checked and More
When should I get my testosterone checked?
Consider getting your testosterone checked if you notice one or more of these signs and they don’t improve with rest, better sleep, or lifestyle changes. Testing should include two early-morning blood tests on separate days, since levels peak in the morning and vary from day to day (Mulhall et al., 2018).
Can low testosterone be reversed?
Sometimes. When low testosterone is linked to factors like excess weight, poor sleep, certain medications, or chronic stress, addressing those causes may improve levels. When it’s caused by a problem with the testicles or pituitary gland, treatment such as TRT may be needed. A provider can recommend the right approach once low testosterone is confirmed through symptoms and blood tests.
At what age does testosterone start to decline?
Testosterone declines gradually with age, but much of that decline is linked to age-related factors like weight gain and illness rather than aging alone (Liu & Reddy, 2022). The rate varies widely between individuals.
What causes low testosterone?
Common causes include aging, obesity, type 2 diabetes, sleep apnea, long-term opioid or corticosteroid use, testicular injury or infection, chemotherapy or radiation, and pituitary disorders (Mulhall et al., 2018).
Can diet and exercise raise testosterone levels?
They can help. Resistance training, reaching a healthy weight, eating a balanced diet, sleeping 7 to 9 hours, and managing stress all support healthy testosterone. Guidelines recommend counseling all men with testosterone deficiency on lifestyle changes as part of treatment (Mulhall et al., 2018). However, lifestyle changes may not fully correct low testosterone caused by a medical or hormonal condition.
Is testosterone replacement therapy right for everyone?
No. TRT is intended for men with confirmed low testosterone and symptoms, and it requires ongoing medical monitoring. It should not be prescribed to men who are currently trying to conceive, because it can suppress sperm production (Mulhall et al., 2018).
Medical Disclaimer
This article is for educational purposes only and does not replace professional medical advice, diagnosis, or treatment. Talk with a qualified healthcare provider before starting, stopping, or changing any medication. Individual results may vary.
