Low Testosterone Symptoms: Signs You Should Get Tested

What is low testosterone?

Testosterone is the main male sex hormone, though women produce it in smaller amounts too. It supports libido, energy, mood, muscle, strength and bone. Levels peak in early adulthood and then decline slowly, at roughly 1% a year from around age 30. Because the fall is so gradual, most men never notice a single turning point, they just feel a bit flatter over time. "Low testosterone" describes levels that have dropped far enough, usually alongside symptoms, to affect how you feel and function. For context, a typical adult male total testosterone sits roughly between 8 and 30 nmol/L, and below 8 nmol/L is the threshold used for subsidised treatment when symptoms and a medical cause are present. Ranges vary by laboratory.

Common symptoms of low testosterone

Low testosterone rarely announces itself. It usually shows up as a cluster of vague changes that build slowly. The most common signs group into three areas.

Physical

• Persistent fatigue and low energy, even after rest
• Loss of muscle mass and strength, or harder recovery from training
• Increased body fat, particularly around the middle
• Reduced body or facial hair
• Disturbed sleep, and in more significant cases, reduced bone density over time

Sexual

• Low libido or reduced interest in sex
• Erectile difficulties
• Fewer spontaneous erections

Mental and mood

• Low mood, irritability or a flat, unmotivated feeling
• Difficulty concentrating or a sense of brain fog
• Reduced drive and confidence

No single symptom confirms low testosterone, and having a few of these does not mean your testosterone is the cause. That is exactly why testing matters: it turns a vague sense that something is off into a clear answer.

Symptoms in men and women

Low testosterone is most discussed in men, but women rely on testosterone too, in much smaller amounts, for libido, energy and muscle. In women, low testosterone can contribute to reduced sex drive and persistent tiredness, often alongside other hormonal shifts around perimenopause. In both sexes, the pattern is the same: the symptoms are real but non-specific, so a blood test is what separates a hormone problem from everything else that feels similar.

What causes low testosterone?

Testosterone can fall for many reasons, and understanding which one matters for what you do next. Doctors broadly split the causes into problems with the testes themselves (primary) and problems with the pituitary or hypothalamus that signal them (secondary), which is why a good panel measures LH and FSH alongside testosterone to help locate the issue. Common contributors include:

• Age, the gradual natural decline from around 30
• Excess weight and type 2 diabetes, which strongly lower testosterone
• Poor sleep and sleep apnoea
• Chronic stress and chronic illness
• Some medications, including opioids and certain steroids
• Heavy alcohol use
• Pituitary or testicular conditions

The good news is that several of these are modifiable. Our guide on how to improve testosterone naturally covers the evidence-based basics, sleep, training, weight and stress, that support healthy levels.

When your symptoms are not low testosterone

This is the part most articles skip, and it is important. The symptoms of low testosterone overlap heavily with other common, treatable conditions, so a low mood or constant fatigue is not proof your testosterone is the problem. Fatigue, low mood and brain fog are also classic signs of an underactive thyroid, low iron, poor sleep and low mood in its own right. That is why testing is so useful: it either confirms testosterone is the driver, or points you to look elsewhere.

If your symptoms lean toward tiredness, weight change, feeling cold or hair thinning, it is worth checking your thyroid at the same time, since thyroid problems are common and easily missed. A broader Male Hormone Profile gives you the full hormonal picture in one test rather than a single marker.

How to know for sure: get tested

Symptoms point, a blood test confirms. To check whether low testosterone is behind how you feel, give a blood sample in the morning, ideally between 7am and 10am, when testosterone peaks. Make sure the test measures free testosterone and SHBG, not just total, because the active fraction is what you actually feel, and a normal total can hide a low free level. A single low result is usually confirmed on a second morning sample before any conclusions are drawn.

With MediTests you can order a Testosterone Test online with no GP referral, walk into any of 3,300+ collection centres, and get results reviewed by AHPRA-registered doctors within 24 to 48 hours. For a step-by-step walk through the process, see how to check your testosterone levels.

What to do if your testosterone is low

A low result is a starting point for a conversation with your doctor, not a diagnosis on its own. Depending on the cause, the first steps are often lifestyle, improving sleep, losing excess weight, reducing alcohol and managing stress, all of which can lift testosterone. Where levels are genuinely low and symptoms are significant, a doctor may investigate further or discuss treatment. Do not self-medicate with testosterone or over-the-counter boosters, get the picture confirmed and guided by a professional.