What Causes Low Testosterone?

You went for your last physical or to get some symptoms checked out because you care about your health, and you haven’t been feeling quite like yourself. You may have been feeling far more fatigued than usual, more irritable, or you’ve lost some of your interest in physical intimacy with your partner. 

Your doctor has indicated that your testosterone levels have come back borderline, or he/she has indicated that they are lower than normal—now you need information.

What causes low testosterone?

A man wearing a white polo shirt and glasses does research on his laptop, perhaps wondering "What causes low testosterone?"

Age Causes Lower Testosterone, But Not Low Testosterone

Age is the first thing you might be inclined to chalk the problem up to. After all, men (and women) experience a gradual decline in testosterone production as they age. However, these natural declines are gradual and usually undetectable.

The generally accepted normal range for a man’s total testosterone is 300-1000 ng/dl, T levels should peak in your 20’s, and it’s considered normal to lose 1% of production per year after age 30. Let’s take a look at an example:

John Fiction has a healthy T level of 750 ng/dl when he turns 30. If we subtract 1% of production every year from a starting level of 750, John would have to live until he was more than 120 before his total testosterone levels would dip below 300 ng/dl.

Further, the average amount of testosterone in a man’s body between the ages of 85 and 100 is usually around 350, requiring another few decades of life for the natural decline to lead to low testosterone. 

So, why does a man in his 40’s or 50’s develop clinically diagnosable levels and the miserable symptoms that come along for the ride? There are causes for chronically low testosterone, which we’ll describe below.

(Though testing your total testosterone level is still the norm, we’ve found that directing therapy by managing your calculated free testosterone levels is much more precise.)

Physical Trauma Causing Primary Hypogonadism

When we talk about hypogonadism (the technical term for Low T) in men, we’re talking about an abnormal medical condition—something that shouldn’t be happening or that’s happening unnaturally.

In men, the majority (over 95%) of testosterone is produced in the testicles, so diseases or disorders of, or even physical damage to, your testicles can result in low testosterone. This is known as primary testicular failure or primary hypogonadism.  

Basically, you have a kind of mechanical malfunction—often more severe and more permanent. Your testicles are no longer able to produce the necessary testosterone for balanced hormone levels due to injury or trauma.

Other possible causes of primary hypogonadism are:

Tumors and cancer also fall under this category, as do their harsh treatment options:

  • Radiation treatment for testicular cancer
  • Surgical removal of one or both testicles

Pituitary Tumors and Other Related Problems Causing Low T

Problems with the pituitary gland or hypothalamus, the parts of the brain that send signals to your testicles that tell them to produce testosterone, can lower your testosterone levels. 

The pituitary gland is a tiny organ about the size of a pea, located in your brain. Tumors in this area can often mimic the function of this gland, producing the wrong hormones or hormones in inappropriate amounts, which throws your overall hormone balance into disarray.

Kallmann’s syndrome, which is an issue of brain development, or a pituitary disorder that disrupts your hypothalamus during puberty from releasing GnRH (gonadotropin hormone), which signals your pituitary gland to produce hormones that trigger testicular function. Therefore, your testicles would produce less testosterone and sperm cells (according to the Cleveland Clinic).

Medications and Illicit Drug Use

Research trends indicate that long-term use of opioids, either by people who must rely on these medications and take them exactly as prescribed to manage their pain and maintain an acceptable quality of life, or by people who who obtain them illegally for their mind-altering effects, can disrupt the production of important hormones in men’s bodies, including:

  • Testosterone
  • Cortisol
  • Estradiol

In fact, according to a study published in Endocrine Reviews by Cassidy Vuong, et al., the primary disorder in men caused by extended opiate use is low testosterone:

“(Patients using opiates) must be aware of not only the prevalence of this disorder on their sexual functioning, but also the effects of the opioids on the other hormones in their system, which may lead to harmful long-term effects.”

Habitual smoking and amphetamine use also affect T levels. Luckily, cessation usually results in a return to normal testosterone levels.

Obesity and Type 2 Diabetes

Choices leading to poor physical condition can negatively affect hormone levels, including testosterone and insulin, which increases the likelihood of diabetes.

In men, the following factors can increase the chances of type 2 diabetes, as well as other hormone imbalances that include Low T:

  • Poor diet
  • Lack of exercise
  • Obesity

Research tells us that obesity and chronic low testosterone often come together as an unfortunate package deal—a vicious cycle we’ve written about many times in the past.

Low T results in inefficient production of lean muscle mass by your body, and more fat tissue is produced instead. That adipose (fat) tissue functions as an estrogen-producing organ, and the resulting estrogen-heavy balance in your system effectively drives down the levels of testosterone available for your body to use. More fat tissue is the result, and down the spiral a man goes.

Whether you were first overweight and that caused Low T levels, or you developed Low T levels that resulted in excess weight gain that worsened the issue, the problem is now a cycle of ill health that must be broken.

Sugary Diets Can Cause Low Testosterone

Sugar can cause your testosterone production to decrease when your body shifts its efforts from producing and releasing testosterone and other hormones in order to dramatically increase insulin production that the body requires to deal with a sudden overload of glucose (sugar).

When testosterone levels are reduced, your estrogen levels effectively increase. An estrogen-heavy imbalance means you’re more likely to hang on to fat and lose muscle.

Habitual heavy sugar intake can also increase the risk of type 2 diabetes and exacerbate the cycle of weight problems and testosterone, trapping you in the cycle mentioned above.

Learn more about how this problem has negatively impacted men in their 20s in particular.

Poor Sleep Quality Can Cause Low Testosterone

The bodies of healthy adult males increase testosterone production, which causes levels to rise, during deep sleep. This is a critical function of the body’s circadian rhythm (the natural, internal process that regulates the sleep-wake cycle and repeats on each rotation of the Earth, or roughly every 24 hours). 

Testosterone levels reach their peak just before awakening, and levels fall throughout the day as our bodies utilize testosterone to fuel critical systems during daily activities.

The growing body of research shows that disturbed sleep hinders this replenishment process and depletes overall testosterone levels. If our bodies don’t receive the rest they need, critical systems fall into a state of general instability, never having enough time or knowing when to repair themselves and restore hormone levels.

The result is chronically insufficient or inconsistent production of testosterone—Low T.

Learn more about the effects of fragmented sleep here

Prolonged or Chronic Stress and Low T

Under stress, your body releases hormones that trigger the fight-or-flight response—a spike in adrenaline and cortisol that switches your body into action and survival mode during short, highly charged situations.

Prolonged stress can cause chronic low testosterone when these elevated levels of cortisol become the norm over long periods of time without the sufficient rest and recuperation that allow your body to reset.

This state wreaks havoc on your hormone balance in the long term. Under these conditions, a person develops chronic fatigue, brain fog, low libido (sex drive), and other symptoms that mimic depression, which is all too often misdiagnosed when the underlying physical cause–low testosterone–is left undetected and untreated.

Learn how dynamic careers can affect your testosterone here.

Low T: What Do I Do Now?

If you’re concerned about Low T, you need the facts about the benefits of TRT (Testosterone Replacement Therapy) and the specific treatment methods we use at Testosterone Centers of Texas found in our comprehensive guide. It answers the most common questions and provides vital information about the treatment of low testosterone.

Read the Guide


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(Augie) Juan Augustine Galindo Jr. MPAS, PA-C

(Augie) Juan Augustine Galindo Jr. MPAS, PA-C started his career in healthcare as a fireman/paramedic in West Texas where he served on the Midland Fire Department from 1998-2004.   He became interested in testosterone treatment after seeing how hormone replacement doctors helped those suffering from low testosterone.   After graduating from the Texas Tech Health Sciences Center Physician Assistant Program, he moved to DFW where he currently lives with his wife and three children.

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