What is
low testosterone?

Testosterone is the main male sex hormone. Low testosterone, sometimes called testosterone deficiency, simply means the body is not producing enough of it to work as it normally would. It is more common than many men realise, and it tends to be talked about less than it should be.

What "low" actually means

Testosterone levels naturally vary from one man to the next, and they shift across the day. Because of that, "low" is not a single number you can read off a home kit. A doctor looks at blood test results alongside your symptoms and your overall health to build the full picture. A level that is low for one man may sit within a normal range for another.

Why levels decline with age

It is completely normal for testosterone to decline gradually as men get older. From around the age of 30, levels tend to ease down slowly, year on year. For most men this gentle decline causes no real trouble. For some, it can contribute to symptoms that affect day to day life, which is when it becomes worth looking at more closely.

Hypogonadism and "andropause"

You may come across the medical term hypogonadism. It refers to the body not producing enough testosterone, whether because of the testicles themselves or the signals sent from the brain. It can be present from a young age or develop later in life.

"Andropause" is an informal term some people use for the slow, age related decline in testosterone. It is not a sudden event like menopause, and it is not a formal diagnosis. Think of it as shorthand for the broader changes some men notice as they age, rather than a condition in itself.

Common symptoms (with an important caveat)

When testosterone is genuinely low, some men notice a cluster of changes over time. These can include:

• Persistent tiredness and low energy
• Reduced sex drive
• Low mood, irritability or poor concentration
• Loss of muscle and changes in body composition
• Disturbed sleep

Here is the catch worth taking seriously: every one of these symptoms has many possible causes, and most have nothing to do with hormones. Stress, poor sleep, other medical conditions and ordinary ageing can all produce the same feelings. Symptoms alone cannot tell you whether testosterone is the reason.

If low mood is your main concern, please also speak with your GP or a mental health professional. If you are in crisis, call 000, or Lifeline on 13 11 14.

How low testosterone is confirmed

The only reliable way to know is a doctor-led assessment together with a blood test, usually a pathology sample taken in the morning when levels are at their highest. The result is read in context, alongside your symptoms and health history, rather than in isolation.

What happens if it is confirmed

If an assessment and blood test confirm low testosterone, a doctor can talk you through the options. Testosterone replacement therapy (TRT) is one possibility, but it is prescription-only, it is not suitable for everyone, and it carries potential risks that a doctor will discuss with you. It is only considered where it is deemed medically appropriate. The first step is simply finding out where you stand.