Testosterone is a sex hormone often associated with males, though females have small amounts. If a male has low testosterone, symptoms can include erectile dysfunction, and males and females may have reduced bone mass and sex drive.
The hormone has many important functions, including:
- the development of the bones and muscles
- the deepening of the voice, hair growth, and other factors related to appearance
- the production of sperm
Testosterone production can slow as a person ages, and many older people experience symptoms of low testosterone.
The American Urology Association defines low testosterone as less than 300 nanograms (ng) of the hormone per deciliter (dl) of blood. The foundation also reports that about 2 in every 100 men have low testosterone.
Below are common signs and symptoms of low testosterone.
Reduced muscle mass
Testosterone plays a role in the development of muscle mass, and reduced levels of the hormone can result in a significant loss of muscle mass.
However, as low testosterone causes a decrease in mass, the function and strength of the muscles do not diminish, according to a
Reduced bone mass
Testosterone helps to produce bone tissue and maintain bone volume. Low testosterone can lead to a reduction in this volume, which can make the bones more susceptible to fractures.
Reduced sex drive
People with low testosterone often experience a reduction in sex drive.
A diminishing sex drive occurs naturally with age, but when the cause is low testosterone, a male will notice a significant decrease in the desire for sex.
A decrease in energy levels
Low testosterone can lead to reduced levels of energy and fatigue.
A person may feel tired, even after adequate rest, or develop a diminished interest in exercise or movement.
An increase in body fat
A reduction in testosterone can lead to an increase in body fat.
In some cases, people with a deficiency of the hormone develop gynecomastia, which causes an enlargement of the breasts.
Many people experience hair loss as a natural part of aging, and age-related hair loss can also affect anyone.
Males may experience specific symptoms of low testosterone levels.
Problems with erections
Low testosterone can make it difficult to achieve or maintain erections. However, low testosterone itself is not always a direct cause of erectile dysfunction. People with high testosterone levels can find it difficult to achieve erections, and people with low levels the opposite.
Testosterone stimulates the penile tissues to produce nitric oxide, which starts several reactions that result in an erection. If levels of the hormone are too low, a man may not be able to get an erection.
Other factors that can cause erectile dysfunction include:
- thyroid-related issues
- high cholesterol
- stress or anxiety
- alcohol consumption
- high blood pressure
Studies show that testosterone replacement therapy can
Reduction in testicle size
A male with low testosterone may notice a reduction in the size of their testicles that is not related to cold temperatures.
The scrotum may also feel softer than usual.
Reduction in the amount of semen
Semen is the fluid that makes up the majority of male ejaculate. This type of fluid helps the sperm move toward the egg.
Testosterone helps stimulate the production of semen, and reduced semen levels can indicate a reduction in testosterone. It can also lead to fertility issues.
People with low testosterone may find it difficult to fall or stay asleep.
Changes in mood or mood swings
Some evidence suggests that people with low testosterone levels are likely to experience a lack of focus, irritability, and depression.
Females may also experience specific low testosterone symptoms, such as the following.
Irregular menstrual cycles
Vaginal dryness is common during and after menopause, but it can occur at any age. It usually results from low estrogen, but low testosterone can also be a trigger.
Testosterone helps the body produce healthy red blood cells (RBCs). Low testosterone levels could lead to anemia, a blood disorder that may occur due to the decrease of RBCs. The main symptom is fatigue.
Testosterone production generally begins to decrease after the age of 30 and after menopause. However, younger people may also have low testosterone levels.
In males, hypogonadism, a condition where the testicles produce little or no testosterone, may occur at any age.
Conditions that may cause hypogonadism include:
- testicular injury or infection
- chemotherapy or radiation cancer treatments
- pituitary gland disease or other hormone disorders
- medications, such as corticosteroids and opiate pain relief
- genetic conditions, such as Klinefelter syndrome
- alcohol and drug abuse
In females, low testosterone levels may result from conditions, such as:
Low testosterone does not always present symptoms, and some people only learn about it after a routine physical examination with blood work.
However, anyone who experiences one or more of the above symptoms should seek medical attention.
To diagnose low testosterone, a doctor will often perform a physical evaluation and review the person’s symptoms. The doctor may also request testing to look for additional signs.
For example, a bone density test can show diminished bone mass, one result of low testosterone.
The most common treatment is testosterone replacement therapy (TRT).
A doctor will typically only prescribe TRT if the person has several symptoms of low testosterone and blood test results that indicate a deficiency.
There are several delivery methods of TRT, including:
- skin patches
- tablets that dissolve in the mouth
- surgically implanted pellets that release the hormone
Most people will notice relief from symptoms within 4–6 weeks of starting TRT.
Weight loss and exercise can often increase testosterone levels naturally.
While changes to the lifestyle and diet alone may not raise levels sufficiently, they can often help.
It is important to remember that males typically lose testosterone as they age, and the potential benefits of lifestyle changes also decrease over time. Exercise, for example, often shows more significant results in younger people.
Eating a balanced diet rich in nutrient-dense whole foods and low in saturated fats may help to boost a person’s testosterone levels.
Can low testosterone cause diabetes?
Testosterone helps the body’s cells increase glucose, or blood sugar, in response to insulin, a hormone that regulates glucose. Reduced testosterone can affect insulin resistance. This can cause the body to produce more insulin to keep glucose levels normal.
When the cells are full of glucose, the body stores the excess in fat cells, which may lead to conditions such as type 2 diabetes and obesity.
Do you consult a urologist or endocrinologist for low testosterone?
According to a 2018
Does low testosterone affect fertility?
However, low testosterone does not cause infertility. In people with fertility problems, low testosterone may be a symptom of a testicular function issue causing infertility rather than a cause of infertility itself.
For example, testicular atrophy can cause infertility and also reduce a person’s testosterone levels. In this instance, the low testosterone levels are a symptom of an underlying condition, not a cause of infertility.
Is low testosterone genetic?
Genetic variants that affect the Y chromosome and the sex hormone-binding globulin may result in a higher risk for low testosterone. SHBG is a protein that helps deliver testosterone to the body’s tissues.
Rare genetic disorders such as Klinefelter syndrome, where males have an extra X chromosome, may also affect testosterone production.
A 2021 study identified 141 new genetic markers that may assist in determining the risk for low testosterone.
The American Urology Association reports that low testosterone affects around 2 in every 100 men. The risk increases with age, though most people naturally lose testosterone as they get older.
Most cases of low testosterone are treatable, and being aware of the symptoms can help a person receive an early diagnosis and treatment.