Male hypogonadism, also known as testosterone deficiency, is a failure of the testes to produce the male sex hormone testosterone, sperm, or both.
This condition can be due to a testicular disorder or the result of a disease process involving the hypothalamus and pituitary gland.
Hypogonadism can have adverse effects on many organ functions as well as negatively influence a male's quality of life. The signs and symptoms of male hypogonadism depend upon the age of onset, the severity of the testosterone deficiency and whether or not there is a decrease in the major functions of the testes.
Because testosterone plays such an important role in a male's reproductive and overall health, any symptoms suggestive of hypogonadism should be discussed with and evaluated by a medical provider.
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Here are some key points about male hypogonadism. More detail and supporting information is in the main article.
- Hypogonadism may occur at any age, and consequences differ according to the age at onset
- If hypogonadism occurs in an infant before birth, sexual ambiguity may result
- If hypogonadism occurs before puberty, puberty does not progress; if it occurs after puberty, hypogonadism can result in infertility and sexual dysfunction
- Males with hypogonadism are at increased risk of bone fractures
- About 50% of men older than 80 years of age have subnormal testosterone levels
- Nearly 50% of older males with low testosterone have no symptoms
- In adult men, symptoms begin within a few weeks of the onset of testosterone deficiency
- A 500% increase in the sales of testosterone formulations in the US has been reported in recent years
- Testosterone blood levels are at their highest in the morning, and in the late summer and early autumn
- Hypogonadism has been shown to increase the risk for cardiovascular disease, type 2 diabetes, metabolic syndrome, premature death in elderly men and Alzheimer's disease.
Causes of male hypogonadism
Hypogonadism in a male refers to a decrease in either or both of the two major functions of the testes: sperm production and testosterone production. There are several causes for this condition.
Primary male hypogonadism is caused by testicular dysfunction that can be congenital or develop later in life.
In primary hypogonadism, the testicles do not respond to hormone stimulation. This can be due to a congenital disorder such as Klinefelter's syndrome, or acquired as a result of radiation treatment, chemotherapy, mumps, tumors or trauma to the testes.
In secondary hypogonadism, a disease state interferes with either the hypothalamus or pituitary gland, the main glands that release hormones to stimulate the testes to produce testosterone.
Situations that can cause secondary hypogonadism include:
- Systemic illness
- Medication side effects
- Liver cirrhosis
- Toxins (alcohol and heavy metals)
- Morbid obesity.
Finally, the term andropause is sometimes used to describe decreased testosterone due to the normal aging process. Testosterone levels in males increase until the age of 17 years. Then, starting at approximately 40 years of age, testosterone levels begin to decline at 1.2-2% per year.
Symptoms of male hypogonadism
Because testosterone affects many tissues, the lack of testosterone can cause many different symptoms.
Symptoms depend on the age of onset, amount of testosterone deficiency and how long the loss has been occurring for. Adolescents and young adults who have not yet completed puberty appear younger than their chronological age. They may also present with small genitalia, a lack of facial hair, failure of the voice to deepen and have difficulty gaining muscle mass in spite of exercise.
Symptoms of puberty-onset hypogonadism:
- Impaired sexual development
- Decreased testicular size
- Enlarged breasts (gynecomastia).
Symptoms of adult-onset hypogonadism:
When hypogonadism develops in adulthood, erectile dysfunction can be a prominent symptom in males.
- Erectile dysfunction
- Low sperm count
- Depressed mood
- Decreased libido
- Sleep disturbances
- Decreased muscle mass and strength
- Loss of body hair (pubic, axillary, facial)
- Osteoporosis and decreased bone mineral density
- Increased body fat
- Breast discomfort and enlargement
- Hot flashes
- Poor concentration and decreased energy.
Risk factors for developing hypogonadism include type 2 diabetes, obesity, renal failure, HIV, hypertension, chronic obstructive pulmonary disease (COPD) and taking glucocorticoid (steroids), opioid or antipsychotic medication therapy.
On the next page, we look at tests and diagnosis of male hypogonadism and the available treatment options for the condition.