What Causes Low Free Testosterone?

What Causes Low Free Testosterone?

7 min read


10 Mar 2022

Testosterone is an essential hormone for men; it has a hand in many processes within the body. Low levels of testosterone can be incredibly damaging to your health. 

However, you can have normal testosterone levels but suffer from low free testosterone, which is equally damaging.

Below is an in-depth look at both conditions, the causes, symptoms and treatments. 

Read on to learn more. 

What Does Low Free Testosterone Mean? 

When you have low levels of free testosterone, it means that you don't have enough testosterone available to enter into the androgen receptor cells. 

Your levels of testosterone might be normal, but it might either be too tightly bound to SHBG or sex hormone-binding globulin, or too much of it might be being converted into dihydrotestosterone or estradiol. 

So low free testosterone can even be a problem for those with normal testosterone levels. 

What Does Low Testosterone Mean?

Low testosterone, or its medical name: male hypogonadism, is a recognized condition

This is because the testes simply do not produce enough testosterone. Low levels of testosterone can lead to low free testosterone but not always. 

The Role of Testosterone in the Body

Testosterone is an important hormone, and it has a hand in regulating a lot of the processes within the body. 

Testosterone has a lot to do with your performance in the bedroom, from erectile function to libido. It also helps build and maintain muscle mass, essential for working on their physique. 

Testosterone helps to stimulate the production of red blood cells in the body, and it helps to promote the formation of new bones, which is crucial when it comes to healing fractures. 

Finally, your testosterone levels can also impact your sense of well-being, as lower levels can lead to feelings of depression. 

Low Testosterone Symptoms & Causes

Having low levels of testosterone is quite common; it is estimated that around forty per cent of men over the age of forty-five have low levels. 

However, it is hard to determine normal testosterone levels because many factors can affect your levels. Everything from your body mass index to the time of day to your nutrition, alcohol consumption, age, and any illnesses you have or medications you take can significantly impact.


The symptoms of low testosterone can vary due to several factors, especially age. 

If you have low testosterone, you may experience a combination of the following symptoms; you won't necessarily experience them all. 

Firstly, you might experience a lower sex drive than usual, which can be coupled with erectile dysfunction. 

You may also have decreased sense of well-being, feelings of depression, difficulty focusing or trouble remembering things. 

In addition, you might feel more fatigued both mentally and physically. You may also experience a loss of muscular strength too.

Other changes could include mild anaemia and a decrease in haemoglobin or bone density, although these are a lot harder to diagnose by yourself. 

In addition, you might notice a thinning or a decrease in your body hair. You may also find yourself putting on weight or developing more breast tissue. 

Men with low testosterone also tend to experience issues with infertility too.


As you age, the production of testosterone naturally slows, and the level in your body tends to drop. This decline tends to start after the age of thirty and continues slowly and steadily for the rest of your life. 

Many different factors can impact your testosterone levels and several potential causes. First and foremost, an injury or trauma to the testes which has interrupted the blood supply. 

An infection of the testes can also lower your testosterone levels. 

As mentioned above, some medications or treatments can also impact your testosterone levels, most predominantly of which is chemotherapy. 

Other medications like opioids, steroids or hormones can also affect your testosterone. 

Some metabolic disorders like an excess of iron can lower your levels. A dysfunction or tumor in your pituitary gland can hinder testosterone production. 

Both acute and chronic illnesses can also be to blame. 

Alcohol abuse, cirrhosis of the liver and chronic kidney failure, all of which are somewhat related, can also suppress testosterone production. 

Inflammatory conditions and syndromes like Kallmann syndrome or Klinefelter can also be blamed. 

Finally, weight on both ends of the spectrum, from extreme weight loss to obesity, can disrupt many systems in the body, including hormone production. 

Congenital disabilities, an excess of estrogen and sleep apnea can also cause low testosterone levels, as can previous anabolic steroid misuse, hypothyroidism, pubertal delay and head trauma. 

In short, many things can affect your testosterone levels and impede your body's hormone production. 

Symptoms & Causes of Low Free Testosterone

Low free testosterone is a lot harder to pinpoint; it is difficult to assess and measure because, as mentioned above, your testosterone levels might be completely normal. 

In addition, it can present itself in a few different ways, and it has its causes. However, there is overlap between the two conditions, which can further muddy the waters and make it hard to pin down. 


In general, men with low free testosterone tend to have poorer health all around. This can present itself as an increase in physical limitations. 

They have lower levels of haemoglobin too. They often report experiencing fewer morning erections, lower libido and less sexual thoughts. 

This can sometimes go hand in hand with higher levels of erectile dysfunction too. 

Lower free testosterone suffers also tend to see a decrease in their bone ultrasound measurements.

Other than a pronounced number of sexual problems, there are a lot of different symptoms of low free testosterone. 

Again, it is worth pointing out that an overlap makes it harder to differentiate between conditions. 

You might find that you have a reduced capacity for exercise, you may also suffer from body stiffness or joint pain. You can gain weight as a result of low free testosterone too. 

Your mental health can take a dive with more feelings of depression and anxiety. You might find it harder to remember things or concentrate on the tasks at hand. 

There could also be an onset of anaemia or a thinning of your hair. 


There are several potential causes of low free testosterone; there is some overlap between the causes of low free testosterone and low testosterone, which is to be expected. 

The first potential cause of low free testosterone is increased SHBG levels, which often occur naturally. Similarly, to causes of low testosterone, an injury or tumor to the testes, hypothalamus or pituitary gland can also cause low free testosterone. 

If you require surgery, radiation, or chemotherapy to treat your tumor, your treatment's side effect could be low free testosterone. 

Obesity and some genetic or medical conditions can also cause low free testosterone, as can alcoholism, steroid, opioid, or just general drug abuse. 

Some prescribed medications may also have the same effect. 

The Effects of Leaving Low Free Testosterone Untreated

If you ignore the signs and symptoms of having low free testosterone, you may be setting yourself up for much more severe health issues. 

Leaving your low free levels untreated can lead to type 2 diabetes, cardiovascular disease or heart attacks, osteoporosis and strokes. 

However, it can also affect your mental capacity to increase your risk of developing dementia or depression. 

The Diagnosis Process 

It can be difficult to diagnose either low testosterone or low free testosterone. The first step is consulting your doctor and telling them of your concerns. 

They can then advise you on the best course of action. The first step is usually a blood test to determine whether or not your testosterone levels are normal

This may have to be done several times because the levels naturally plateau throughout the day anyway. If the levels are low, your doctor can advise you on treatments. 

On the other hand, if your levels come back normal, further testing will be needed to determine whether you have low free testosterone. 

Is it Preventable?

In short, no. There are no known preventative measures that you can take to prevent your testosterone levels from lowering. 

Frequently, a lower level is caused by a genetic condition or some form of damage to the testes or pituitary gland, which would be incredibly difficult to avoid. 

Committing to a healthy lifestyle can help keep your levels within the normal range. 

There are several natural ways to boost your testosterone. Including stress management, you are getting enough sleep and eating well. 

In addition, if you do suffer from low free testosterone, then boosting your levels, whether they fall into the normal range or not, can help to increase your free testosterone. 

You may even want to try testosterone boosters as a way to encourage your body to produce more testosterone naturally. 

In Conclusion

Low levels of testosterone free or otherwise can have detrimental effects on your health in several aspects. 

The symptoms of both conditions are far-reaching. 

If you notice any of the symptoms listed above, you should reach out to your doctor for some tests.