Definition
What is low testosterone?
Low testosterone — clinically known as hypogonadism — is a confirmed deficiency of the male sex hormone testosterone, diagnosed when two morning blood tests show a level below the normal adult male range and the man has matching symptoms.
Quick facts
- Medical name
- Hypogonadism
- Diagnostic threshold (AU)
- <8 nmol/L total testosterone
- Confirmation
- Two morning fasting tests
- Symptoms
- Can overlap with other health conditions
- First-line treatment
- Address cause + TRT if indicated
- PBS-subsidised
- Yes, with specialist authority
The clinical definition
The Royal Australian College of General Practitioners (RACGP) and the Endocrine Society of Australia define low testosterone as a serum total testosterone below the local laboratory's reference range — typically 8 nmol/L — confirmed on two separate early-morning blood tests, in the presence of consistent symptoms. A single low reading is not a diagnosis.
Symptoms of low testosterone
- Persistent fatigue not relieved by sleep
- Reduced libido (sex drive)
- Erectile dysfunction or fewer morning erections
- Loss of muscle mass and strength
- Increased body fat, particularly around the abdomen
- Low mood, irritability or "brain fog"
- Reduced bone density (over time)
How low testosterone is diagnosed in Australia
- Symptom screen — the validated ADAM questionnaire identifies men who should be tested.
- Morning fasting blood test (before 10am) — total testosterone, SHBG, LH, FSH.
- Repeat test on a separate morning if the first is low.
- Specialist referral (endocrinologist, urologist or sexual health physician) if confirmed.
Related conditions
- Hypogonadism — the umbrella medical term.
- Primary hypogonadism — testicular failure.
- Secondary hypogonadism — pituitary/hypothalamic failure.
Clinical sources
- [1]RACGP. Testosterone use in adult males — clinical guideline
- [2]Endocrine Society of Australia · Medical Journal of Australia. Male hypogonadism position statement, part 1: assessment
- [3]Healthdirect Australia. Testosterone: symptoms, causes and assessment
- [4]Endocrine Society of Australia · Medical Journal of Australia. Male hypogonadism position statement, part 1: assessment
People also ask
What is considered low testosterone in Australia?+
Australian labs use a reference range of roughly 8–30 nmol/L for total testosterone. A morning level below 8 nmol/L on two separate occasions, with symptoms, is the standard threshold for low testosterone (hypogonadism).
Is low testosterone the same as low T?+
Yes — "low T" is the everyday term for clinically low testosterone, medically known as hypogonadism. Both describe a confirmed deficiency of the male sex hormone testosterone.
What causes low testosterone in men?+
Causes include testicular or pituitary conditions, obesity, type 2 diabetes, sleep apnoea and other health conditions. Your doctor assesses possible causes rather than assuming symptoms are due to age alone.
Is low testosterone serious?+
Long-term untreated low testosterone is linked to reduced bone density, muscle loss, anaemia, depression, cardiovascular risk and infertility. It is treatable — the first step is a morning blood test.
Can low testosterone be reversed naturally?+
Mild cases linked to obesity, poor sleep, or untreated diabetes often improve with weight loss, sleep apnoea treatment and exercise. Genuine hypogonadism caused by testicular or pituitary failure usually needs medical treatment.
Take the free 2-minute symptom check
The ADAM symptom check shows whether your symptoms may be worth discussing with a doctor. You can also request a callback to get matched with a men's health doctor at a partner clinic, by telehealth or in person, for an assessment.
Start the free assessmentWant to talk to someone first? Read how getting matched with a doctor works.
*Blood tests may be bulk billed where eligible, subject to doctor assessment and clinical indication.