Signs of Low Testosterone in Men: When to Get Tested

The most common signs of low testosterone in men are low sex drive, ongoing fatigue, loss of muscle, more belly fat, low mood, and trouble with erections. If you notice two or more of these lasting longer than a few weeks, it is time to get tested. A simple morning blood test, repeated to confirm the result, is the only way to know your levels for sure. This guide covers the Signs of Low Testosterone in Men: When to Get Tested, how symptoms shift with age, and what the testing process looks like.

At Regeneris Medspa in Westwood, Dr. Ryan Welter, MD, PhD, evaluates men for hormone imbalance as part of our Bioidentical Hormones services.

What Is Low Testosterone

Testosterone is the main male sex hormone. It is made mostly in the testicles. It supports sex drive, sperm production, muscle mass, bone strength, red blood cell production, energy, and mood.

Low testosterone, also called low T or hypogonadism, means the body is not making enough of this hormone. Levels naturally drop by about 1% per year after age 30. For some men, the drop is steeper or starts earlier, and symptoms follow.

Low T can come from a problem in the testicles or from a problem in the brain’s signals that tell the testicles to make testosterone. Weight gain, poor sleep, certain medications, and chronic illness can also lower levels.

Early Signs of Low Testosterone

Early signs are often easy to miss. Many men blame them on stress, work, or getting older. Watch for these first changes:

• Lower interest in sex. This is often the earliest and most noticeable sign.

• Less energy in the afternoon. You feel drained even after a full night of sleep.

• Fewer morning erections. A drop in spontaneous erections can point to a hormone change.

• Slower workout recovery. Strength gains stall, and soreness lasts longer.

• Shorter patience. Irritability or a flat mood shows up more often.

One of these alone does not confirm low T. A pattern of several, building over months, is worth paying attention to.

Common Symptoms to Watch For

As levels stay low, symptoms tend to become clearer. Common ones include:

• Sexual changes: low libido, weaker erections, and reduced semen volume.

• Body changes: loss of muscle mass, more fat around the waist, and reduced strength.

• Energy and sleep: constant tiredness, poor sleep, and less drive to stay active.

• Mood and focus: feeling down, low motivation, and trouble concentrating.

• Physical signs: thinning body hair, hot flashes, and breast tissue tenderness or swelling.

Many men also describe feeling “not like myself.” That general sense of decline is a valid reason to look deeper.

Signs by Age Group

Low Testosterone in Your 20s and 30s

Younger men can have low T, though it is less common. When it happens at this age, there is often a specific cause. Possible causes include:

• Past anabolic steroid use

• Heavy alcohol or opioid use

• Obesity or poor sleep

• Testicle injury or past mumps infection

• Genetic conditions

• Problems with the pituitary gland

In this age group, symptoms such as low libido, trouble building muscle, and fertility problems tend to stand out. Because a cause is more likely, testing is especially useful. Treatment choices may also differ for men who still want children, since some therapies reduce sperm production.

Low Testosterone After 40

After 40, the gradual yearly decline starts to add up. Symptoms often creep in slowly, which makes them easy to dismiss as normal aging.

Common signs at this stage include weight gain around the middle, lower energy, slower recovery, and reduced sex drive. Weight gain and low testosterone also feed each other. Extra body fat converts testosterone into estrogen, which can push levels even lower.

Symptoms in Your 50s and Beyond

Men in their 50s and older are more likely to have low T alongside other health conditions. Diabetes, heart disease, and sleep apnea are all linked to lower testosterone.

At this age, watch for loss of muscle and strength, lower bone density, poor sleep, and changes in mood or memory. Erectile problems are also more common. These can come from low T, blood vessel problems, or both.

Low Testosterone vs. Other Conditions

Many low T symptoms overlap with other health problems. That is why symptoms alone are not enough for a diagnosis. Conditions that can look similar include:

• Thyroid problems: an underactive thyroid causes fatigue, weight gain, and low mood.

• Depression: low mood, low energy, and low sex drive are common to both.

• Sleep apnea: poor sleep drains energy and can also lower testosterone.

• Anemia: low red blood cells cause tiredness and weakness.

• Diabetes: high blood sugar can cause fatigue and erectile problems.

• Medication side effects: some antidepressants, opioids, and steroids affect energy and libido.

A full evaluation looks at the whole picture rather than one lab number. Treating the wrong cause wastes time and leaves the real problem in place.

When to Consider Testosterone Testing

Knowing the Signs of Low Testosterone in Men: When to Get Tested helps you act early rather than waiting for symptoms to pile up. Consider testing if:

• You have two or more symptoms that have lasted longer than a few weeks.

• Your sex drive has dropped without a clear reason.

• You are gaining belly fat or losing muscle despite steady habits.

• You and your partner are having trouble conceiving.

• You have diabetes, obesity, or sleep apnea.

• You have a history of steroid use or testicle injury.

• You have had a bone fracture from a minor fall.

You do not need to wait until symptoms are severe. Earlier testing gives you a baseline and more options.

Men who also have concerns about sexual function can learn about our sexual wellness services, including P stem.

How Low Testosterone Is Diagnosed

How Testosterone Is Tested

Testosterone is measured with a blood draw. Timing matters. Levels are highest in the morning and drop through the day, so testing is usually done early in the morning.

Total testosterone is the most common first test. Many labs consider levels below about 300 ng/dL as low, though symptoms matter as much as the number. Your provider may also check:

• Free testosterone: the portion your body can actually use.

• LH and FSH: brain hormones that show whether the problem starts in the testicles or the pituitary gland.

• Estradiol: a form of estrogen that can rise as testosterone falls.

• Prolactin: a hormone that can lower testosterone when elevated.

• Complete blood count, thyroid, and metabolic labs: to rule out other causes.

Dr. Ryan Welter, MD, PhD reviews lab results alongside your symptoms, health history, and goals before recommending any next step.

Do You Need More Than One Blood Test

Yes, in most cases. Testosterone levels can vary from day to day. Illness, poor sleep, heavy exercise, or alcohol the night before can all lower a single reading.

A diagnosis of low T usually requires two separate morning tests showing low levels. A second test confirms the result and helps avoid treatment that is not needed.

Conclusion

Low testosterone often shows up as low sex drive, fatigue, muscle loss, belly fat, and mood changes. Symptoms can appear at any age, but they become more common after 40. Because many conditions look similar, two morning blood tests are needed to confirm a diagnosis. Reviewing the Signs of Low Testosterone in Men: When to Get Tested is a good first step. A full evaluation with Dr. Ryan Welter, MD, PhD at our Westwood office, including a look at regenerative medicine options, can show you what is really going on.