Low testosterone

Symptoms & causes

What is testosterone?

Testosterone is the most important androgen (male sex hormone) in men and it is needed for normal reproductive and sexual function. Testosterone is important for the physical changes that happen during male puberty, such as development of the penis and testes, and for the features typical of adult men such as facial and body hair. Testosterone also acts on cells in the testes to make sperm.

Testosterone is also important for overall good health. It helps the growth of bones and muscles, and it affects mood, libido (sex drive) and certain aspects of mental ability.

How is testosterone production controlled?

The pituitary gland and the hypothalamus, located at the base of the brain, control the production of male hormones and sperm. Luteinizing hormone (LH) and follicle stimulating hormone (FSH) are the two important messenger hormones made by the pituitary gland that act on the testes. LH is needed for the Leydig cells in the testes to make testosterone.


What is androgen (or testosterone) deficiency?

Androgen, or testosterone, deficiency is when the body is not able to make enough testosterone for the body to function normally. Although not a life-threatening problem, androgen deficiency can affect your quality of life.

How common is androgen deficiency?

Androgen deficiency affects about one in 200 men under 60 years of age. It is usually caused by a genetic disorder or damage to the testes or, in rare cases, a lack of hormones made by the brain.

It is thought that about one in 10 older men may have low testosterone levels but exact numbers are not known. It is likely that androgen deficiency is under-diagnosed and that many men are missing out on the benefits of treatment.

How does ageing affect testosterone levels?

Testosterone levels in men are highest between the ages of 20 and 30 years. As men age there is a small, gradual drop in testosterone levels; they may drop by up to one third between 30 and 80 years of age.

Some men will have a greater drop in testosterone levels as they age. This is more likely when men are obese or have other chronic (long-term) medical problems.

What are the symptoms of androgen deficiency?

Low energy levels, mood swings, irritability, poor concentration, reduced muscle strength and low sex drive may be symptoms of androgen deficiency (low testosterone). Symptoms often overlap with those of other illnesses. The symptoms of androgen deficiency are different depending on the age when testosterone levels are below the normal range.

Stages Of lifePossible symptoms
Early childhood• Penis and testes do not grow to expected size
Early teenage years (puberty)• Failure to go through full normal puberty
• Poor development of facial, body or pubic hair
• Poor muscle development
• Voice does not deepen • Poorgrowth(height)surge
• Breast development (gynaecomastia)
Adulthood• Mood changes (low mood and irritability)
• Poor concentration
• Low energy
• Reduced muscle strength
• Increased body fat
• Longer time to recover from exercise
• Decreased libido (low interest in sex)
• Difficulty getting and keeping erections
• Low semen volume
• Reduced beard or body hair growth
• Breast development (gynaecomastia)
• Hot flushes, sweats
• Osteoporosis (thinning of bones)
Later life (after 60 years)• Mood changes (low mood and irritability)
• Poor concentration
• Easily fatigued
• Poor muscle strength
• Increased body fat
• Decreased libido (low interest in sex)
• Difficulty getting and keeping erections
• Breast development (gynaecomastia)
• Osteoporosis (thinning of bones)


How is androgen deficiency diagnosed?

A diagnosis of androgen deficiency involves a number of steps including a full medical history and physical examination, and at least two blood samples, taken in the morning on different days, to measure hormone levels.

A diagnosis of androgen deficiency is only confirmed when blood tests show a lower than normal testosterone level.


How is androgen deficiency treated?

Androgen deficiency is treated with testosterone therapy; this means giving testosterone in doses that return the testosterone levels in the blood to normal. Testosterone is prescribed for men with confirmed androgen deficiency. Once started, testosterone therapy is usually continued for life and needs to be checked regularly by a doctor.

What are the main forms of testosterone therapy?

Testosterone therapy, available in Australia in the form of injections, gels, lotions, patches, and capsules and tablets, works very well for men with confirmed androgen deficiency. The type of treatment prescribed can depend on patient convenience, familiarity and cost.

What are the side-effects of testosterone therapy?

Testosterone therapy can increase prostate growth which can increase the symptoms of benign prostate enlargement (such as needing to urinate more often). For men with prostate cancer, testosterone can make the cancer worse and should not be prescribed.

Other side-effects are uncommon. Mild acne, weight gain, gynaecomastia (breast development), male-pattern hair loss and changes in mood (including increased aggression) can happen and should be managed by a doctor.

Will testosterone therapy affect my fertility?

Testosterone therapy generally stops the production of the pituitary hormones FSH and LH, which reduces the size of the testes and can lower or stop sperm being made. If sperm production was normal before testosterone therapy, it usually recovers after treatment stops but it can take many months to go back to normal.


Does male menopause exist?

Terms such as ‘male menopause’ or ‘andropause’ are not accurate. Menopause is the stopping of menstrual cycles (periods) that happens in all women as they age. Testosterone levels in men do not stop suddenly but slowly drop with age. Not all men will have a drop in testosterone as they get older. The hormone changes with ageing in men and women are diagnosed and treated differently.

Are there any herbal products for androgen deficiency?

There are many herbal products marketed, particularly on the Internet, as treatments that can act like testosterone and improve muscle strength and libido (sex drive). However, there are no known herbal products that can replace testosterone in the body and be used to treat androgen deficiency.

Can I do anything to prevent androgen deficiency?

There are no known ways to prevent androgen deficiency that is caused by damage to the testes or pituitary gland. However, if you live a healthier lifestyle and manage other health problems your testosterone levels may improve, if your low testosterone levels are caused by other illness.

Not all men have a drop in testosterone levels with age. A healthy lifestyle may help you to keep testosterone levels normal.

Last modified: February 20, 2015
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