Low Testosterone Symptoms in Men: Signs, Causes and Testing in Australia

What are the signs of low testosterone?

The common signs of low testosterone fall into sexual, physical and emotional groups. Healthy Male and healthdirect, two Australian health information services, list similar symptoms [1][2][3], and every one of them can also have other causes.

What Australian health bodies list

healthdirect [1], the government-funded health information service, lists reduced libido, erection problems, poor sleep, hot flushes, lower energy, low mood and trouble concentrating or remembering. Physical changes it lists include more body fat, less muscle, tender breasts, less body hair, infertility and lower bone density.

Healthy Male [2], the national men's health organisation, lists similar symptoms. It adds signs a doctor may look for on examination, such as very small testes and breast tissue growth (gynaecomastia).

Specific and non-specific signs

A 2019 RACGP article on androgen deficiency in older men [4] describes breast tissue growth, recent loss of body hair and shrinking testes as more specific signs. Fatigue, low libido and reduced muscle bulk are non-specific, because almost any long-term illness can cause them.

If changes in erections are your main concern, healthdirect recommends [5] talking to your doctor, as they can be an early sign of heart disease or diabetes.

What else can cause the same symptoms?

Tiredness, low libido, poor sleep and low mood often have other causes. Sleep problems, stress, depression, excess weight, alcohol and some medicines can produce similar symptoms, and several are also linked with lower testosterone readings.

The RACGP article [4] says most men with these non-specific symptoms don't have a disease of the testes or pituitary. More often, general health is suppressing testosterone, so a doctor will ask about sleep, mood, drinking, weight and medicines.

healthdirect advises [8] seeing a doctor if fatigue lasts more than two weeks and isn't improving, and recommends seeing your GP [9] if low mood lasts two weeks or more.

What causes low testosterone?

Low testosterone happens when the testes don't make enough, or the pituitary gland doesn't signal them properly. healthdirect [1] lists causes including testicular injury, pituitary damage, obesity, genetic conditions, diabetes, haemochromatosis (iron overload), tumours, and some medicines and cancer treatments.

Doctors group causes into three types.

• Primary hypogonadism. The problem is in the testes, for example genetic conditions, undescended testes, injury, mumps or haemochromatosis (Healthy Male [2]).

• Secondary hypogonadism. The problem is in the pituitary gland or hypothalamus, which signal the testes. Examples include Kallmann syndrome and pituitary disease or injury (Healthy Male [2]).

• Functional causes. The hormone system is intact but suppressed by other health problems. The Endocrine Society of Australia [11] links obesity, metabolic syndrome and type 2 diabetes with lower testosterone, and Healthy Male [2] notes short-term illness can lower it too.

Klinefelter syndrome, where a male has an extra X chromosome, is the most common genetic cause. It affects at least 1 in 500 Australian males (Healthy Male [12]), and up to 75% are never diagnosed (Healthy Male [2]).

Low testosterone causes in younger men and men in their 30s

In men in their 20s and 30s, low testosterone is more likely to have a specific cause than to reflect age. RACGP [4] notes that disease of the testes or pituitary can occur at any age.

A doctor may consider:

• Klinefelter syndrome, which Healthy Male [13] says is sometimes only found when a man tries to start a family

• a past testicular problem, such as undescended testes, injury or mumps (Healthy Male [2])

• past use of performance-enhancing hormones, after which Healthy Male says [14] natural production can take many months to recover

• excess weight, poor sleep and long-term health conditions (Healthy Male [14])

How do testosterone levels change with age?

Testosterone levels peak in early adulthood, then tend to fall slowly. In healthy men the fall is small, and Australian research links much of it to weight gain and health problems rather than age alone.

Levels peak in adolescence and early adulthood, and any later drop is usually small (Healthy Male [14]).

Healthy Male [12] estimates how many men are affected by lower testosterone linked with ageing:

Pooled data from 10,904 samples in Australian population studies showed a gradual decline from 35 and a more marked decline after age 80 [15].

Australian studies show the drop is small in healthy men.

• Healthy Male [16] describes the normal age-related decline as about 1% a year, and says this decline alone is not androgen deficiency.

• The Florey Adelaide Male Ageing Study [17] followed 1,382 men aged 35 and over for five years. Average testosterone went from 16.2 to 15.6 nmol/L. The authors linked the fall with obesity, depression and chronic disease, and concluded the decline is not inevitable.

• Healthy Male [14] says healthy older men of normal weight usually don't have a significant drop, and there is no "male menopause".

What is a normal testosterone level for my age?

There is no single normal testosterone level. Australian laboratories report total testosterone in nanomoles per litre (nmol/L) against their own reference interval, which Pathology Tests Explained [10] says varies with the laboratory, testing method and age. A result flagged high or low doesn't necessarily mean anything is wrong, and your doctor needs your history to interpret it. For more on reading results, see our guide to understanding blood work and pathology.

Is hypogonadism the same as low testosterone?

Not exactly. Hypogonadism, also called androgen deficiency, is a diagnosis that needs low testosterone plus matching signs and symptoms. A single low blood result is not the same thing.

• Low testosterone. A blood result below the reporting laboratory's reference interval.

• Androgen deficiency. Healthy Male [16] defines it as a low testosterone level accompanied by signs and symptoms, and says a low level alone does not count.

• Pathological hypogonadism. The Endocrine Society of Australia [11] describes it as a clinical diagnosis confirmed by hormone blood tests, caused by disease of the testes, pituitary or hypothalamus.

• Functional hypogonadism. Lower testosterone caused by obesity or chronic illness without a structural problem. RACGP [4] describes it as potentially reversible.

How is low testosterone tested in Australia?

Low testosterone is tested with an early-morning blood test for total testosterone, when levels are highest. Levels vary from day to day, so a low result is usually repeated on another day.

A doctor will usually follow these steps.

1. Timing. healthdirect [1] advises an early-morning test while fasting. The RACGP article [4] notes that eating can lower testosterone by up to 25%.

1. Repeat testing. Levels can vary by up to 30% day to day, so RACGP [4] says never to diagnose on one low result. Healthy Male [16] calls for at least two samples on separate days.

1. Related hormones. Luteinising hormone (LH) and follicle-stimulating hormone (FSH) are usually measured too, to help locate the problem (Endocrine Society of Australia [11]). Sex hormone binding globulin (SHBG) may be added (Pathology Tests Explained [10]).

1. Other checks. A doctor may check iron levels for haemochromatosis or order a genetic test for Klinefelter syndrome (healthdirect [1]).

1. Being well. Any illness can suppress testosterone, so RACGP [4] advises testing when you are well.

Read what a hormone blood test covers. Our guides to blood tests before a telehealth consultation and private blood tests in Australia explain how pathology requests and collection work.

What happens in a doctor's assessment?

A Regeniq assessment starts online, with an independent Australian doctor who decides whether tests are needed and what, if anything, happens next.

1. Online questionnaire. You answer questions about your symptoms, health history and any medicines you take.

1. Telehealth consultation. You talk with an independent Australian doctor about your symptoms and history.

1. Morning blood tests, if requested. If the doctor requests pathology, you attend an early-morning collection with a third-party pathology provider.

1. Review of results. The doctor weighs your results alongside your symptoms and history and decides what is suitable. That can be no action, a repeat or further test, or a referral back to your GP.

If tests suggest low testosterone, the next step is usually confirming the result with a repeat morning test and looking for a cause. The Endocrine Society of Australia [11] says review by an endocrinologist may be warranted in some situations.

Regeniq does not prescribe, diagnose, compound or dispense; independent clinicians do.

You can read more about what a hormonal health assessment covers and how Regeniq works.

Common questions about low testosterone

Can men in their 30s have low testosterone?

Yes. Low testosterone can occur at any age. In younger men it is more likely to have a specific cause, such as Klinefelter syndrome, a past testicular problem or past use of performance-enhancing hormones, according to RACGP [4] and Healthy Male [2].

Is low testosterone common in men over 60?

It becomes more common with age. Healthy Male [12] estimates more than 1 in 30 men aged 60 to 69 and about 1 in 20 men aged 70 to 79 have lower testosterone linked with ageing, often alongside conditions such as obesity or diabetes.

What time of day should a testosterone blood test be done?

Early in the morning, usually while fasting, because testosterone levels are highest then. healthdirect [1] says a low result needs a second test to confirm it.

What is a normal testosterone level for a man?

There is no single normal level. Australian laboratories report testosterone in nmol/L against their own reference intervals, which vary between laboratories and age groups, according to Pathology Tests Explained [10]. A doctor interprets the result alongside your symptoms and history.

Can stress or poor sleep cause symptoms like low testosterone?

Yes. Stress, poor sleep, depression and alcohol can cause tiredness or low mood (healthdirect [8]), and poor sleep is linked with lower testosterone readings (Healthy Male [14]).