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  • Writer's pictureFabio Castiglione

Low Testosterone

Updated: Jan 7, 2023

When low testosterone levels occur in the blood, it is called hypogonadism. In this article we will look at the causes, the ailments it causes and how low testosterone levels can be treated.

Hypogonadism occurs when the sex glands called gonads produce little or no sex hormones. It affects teenagers and adults. The condition causes, among other things, a low sex drive or libido. Dr. Fabio Castiglione is a Specialist in Urology and Andrologist in London, Dr. Castiglione is dedicated to male sexual problems. Unlike other colleagues, he is specifically concerned with male sexuality. This means that he knows how to put you at ease and that he can solve your problem.

Is hypogonadism common in men?

Low testosterone affects nearly 40% of men aged 45 and over. It is difficult to define normal testosterone levels, because levels vary throughout the day and are influenced by body mass index (BMI), diet, alcohol consumption, certain drugs, age and disease.

It may be due to a testicular disorder or the result of a pathological process involving the hypothalamus and the pituitary gland. Hypogonadism can affect many organ functions and can have a negative impact on the quality of life.

Identifying this condition is very important because testosterone helps maintain and develop:

  • Sexual characteristics.

  • Muscle mass.

  • Adequate levels of red blood cells.

  • Bone density.

  • Sense of well-being.

  • Sexual and reproductive function.

What are the types of hypogonadism?

Two glands in the brain, the hypothalamus and the pituitary, send signals to the sex glands. These signals tell your body to make sex hormones. When you have hypogonadism, something in the brain or sex glands is interfering with hormone production.

Healthcare professionals examine the cause to determine if hypogonadism is:

Primary hypogonadism: a problem within the sex glands slows down or stops the production of hormones. This may be due to a congenital disorder such as Klinefelter's syndrome or acquired as a result of radiation therapy, chemotherapy, mumps, tumors, or trauma to the testicles.

Secondary (central) hypogonadism: A problem with brain signals affects hormone production.

Situations that can cause secondary hypogonadism include:

  • Malnutrition.

  • Systemic disease.

  • Fatigue.

  • Side effects of drugs.

  • Cirrhosis of the liver.

  • Toxins (alcohol and heavy metals).

  • Pathological obesity.

What are the symptoms of hypogonadism?

The signs and symptoms depend on when it starts, how severe the deficiency is and whether or not there is a decrease in the main functions of the testicles. Symptoms of low testosterone depend on the person's age and include the following:

  • Low sexual desire.

  • Erectile dysfunction.

  • Decreased sense of well-being.

  • Depressed mood.

  • Difficulty in concentration and memory.

  • Fatigue.

  • Bad mood and irritability.

  • Loss of muscle strength.

Other changes that occur with low testosterone levels include:

Decrease in hemoglobin and mild anemia.

A decrease in body hair.

Thinning of the bones (osteoporosis).

Increased body fat.

Breast development (gynecomastia).


What are the causes of low testosterone?

As a man ages, the amount of testosterone in his body gradually decreases. This natural decline begins after the age of 30 and continues (about 1% per year) throughout life. However, there are a number of potential causes for low testosterone levels that explain why this condition can affect even the youngest; including:

Injury (trauma, interruption of the blood supply to the testicles) or infection of the testicles (orchitis).

Chemotherapy for cancer.

Metabolic disorders such as hemochromatosis (too much iron in the body).

Dysfunction or tumors of the pituitary gland.

Medicines, including opioids, hormones used to treat prostate cancer, and steroids (such as prednisone).

Acute (short-term) or chronic (long-term) disease.

Alcohol abuse.

Cirrhosis of the liver.

Chronic renal failure (kidney).


Inflammatory conditions such as sarcoidosis (a condition that causes inflammation of the lungs and other organs).

Kallman syndrome (abnormal development of the hypothalamus, a gland in the brain that controls many hormones).

It's still….

Klinefelter syndrome (a genetic condition in which a male is born with an extra copy of the X chromosome). Also called XXY syndrome.

High levels of prolactin, the hormone that produces milk.

Obesity or extreme weight loss.

Uncontrolled type 2 diabetes mellitus.

Congenital defect (present at birth).

Obstructive sleep apnea.


Excess estrogen (usually from an external or environmental source).

Previous abuse of anabolic steroids.

Severe primary hypothyroidism.

Pubertal delay.

Trauma (head injury).

Radiation exposure or previous brain surgery.

How is low testosterone diagnosed?

Low testosterone is diagnosed by measuring the amount of testosterone in the blood with a simple blood test. It may take several measurements to determine if a patient has low testosterone, as levels tend to change throughout the day. The highest testosterone levels are generally in the morning, around 8 in the morning. This is why doctors prefer to measure testosterone levels early in the morning.

The importance of early diagnosis in boys

Early detection in boys can help prevent the problems of delayed puberty. The doctor will carry out a physical exam and note if sexual development, such as pubic hair, muscle mass and testicular size, is consistent with age. Your doctor will examine your blood testosterone level if you have any signs or symptoms of hypogonadism. If the tests confirm that there is a low level of testosterone, further tests can determine whether the cause is a testicular disorder or a pituitary abnormality. These studies could include:

Hormone tests.

Semen analysis.

Pituitary imaging.

Genetic studies.

Testicular biopsy.

How are patients with hypogonadism treated?

Treatments for hypogonadism vary according to the cause. For primary hypogonadism, hormone replacement therapy can increase hormone levels. Men can undertake a therapy that involves taking testosterone. These treatments are available in gels, implants, pills, injections and skin patches. If a pituitary gland problem such as a tumor causes secondary hypogonadism, you may need medication, radiation therapy, or surgery. Low testosterone is treated with testosterone replacement therapy, which can be administered in several ways:

Intramuscular injections (into a muscle), usually every 10-14 days.

Testosterone patches, which are used daily and are applied to different parts of the body, including buttocks, arms, back and abdomen.

Testosterone gels that are applied every day to clean, dry skin on the upper back and arms (gels require attention to ensure that the hormone is not accidentally transferred to another person or partner).

Pellets that are implanted under the skin every two months.

What are the benefits of testosterone therapy?

The potential benefits of testosterone replacement therapy can include:

In boys, avoid problems related to delayed puberty.

Fat loss.

Increased bone density and protection against osteoporosis.

Improvement of mood and sense of well-being.

Improved sexual function.

Greater mental acuity.

Greater muscle strength and physical performance.

The Side Effects of Testosterone Therapy!

Side effects of testosterone replacement therapy include:

Acne or oily skin.

Swollen ankles caused by mild fluid retention.

Stimulation of the prostate, which can cause urination symptoms such as difficulty urinating.

Breast enlargement.

Worsening of sleep apnea (a sleep disorder that causes frequent nocturnal awakenings and daytime sleepiness).

Smaller testicles.

Skin irritation (in patients receiving topical testosterone replacement)

Laboratory abnormalities that can occur with testosterone replacement include:

Increased prostate specific antigen (PSA).

Increased red blood cell count.

Decreased sperm count, which produces infertility (inability to have children), which is especially important in younger men who desire fertility.

It is clear that those who undertake hormone replacement therapy will have to undergo a series of regular follow-ups with their doctor.

The importance of diagnosis for the prostate

Testosterone replacement therapy can cause prostate growth. If a man has early stage prostate cancer, there is a fear that testosterone may stimulate cancer growth. Therefore, men who have prostate cancer should not take testosterone replacement therapy. It is important that all men considering testosterone replacement therapy undergo a prostate screening before starting this therapy.

For patients who choose monitoring, doctors must assess the risk of prostate cancer before starting testosterone treatment and 3 to 12 months after starting testosterone:

PSA levels should be checked at 3, 6 and 12 months within the first year and annually thereafter.

A digital rectal examination of the prostate should be performed 3-6 months and 1 year after the start of therapy, and every year thereafter. This is also recommended for men who are not on testosterone replacement therapy, as a screening for age-related prostate cancer. This usually begins at the age of 50.

The hematocrit levels will be checked before the start of testosterone therapy, then on a regular basis to make sure that the red blood cell levels remain normal.

When should you call the doctor?

urologist London

You should call your doctor if you experience:

Erectile dysfunction or enlarged breasts (in males).

Low sexual desire.

Slow onset of puberty (in adolescents).


Low testosterone is a condition that needs the utmost attention from a specialist. As we have mentioned in this article, causes and solutions depend a lot on the cause. It is therefore important to establish the cause of the disorder with certainty, and to remedy it. We hope to have been able to give a general overview on the subject but if this is not the case, or if you have other questions on the subject, Dr. Castiglione and his staff will be happy to assist you.

HolisticAndrology, urology clinic in London, has always been at the forefront to improve the quality of life for all people suffering from Impotence. If you are interested and want more information, do not hesitate to contact us.

Contact HolisticAndrology, andrology clinic in London (tel. +44 (0) 7830398165) to book an andrological consultation with dr. Fabio Castiglione, Urologist London.

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