Symptoms of Low Testosterone

Written by
The Manual Team
Medically approved by
Dr Earim Chaudry
Last updated
7th January 2022

In 30 seconds…

Testosterone is a sex hormone produced in the testicles. We tend to think of it as the thing in charge of all things “male” (although women do have it too). Think muscle and bone mass, fat distribution, facial hair, sperm production – and your libido. It’s important stuff.
The symptoms of low testosterone (or Low-T) can be both physical and mental. It can cause a range of sexual dysfunctions – like erectile dysfunction, reduced semen production, and a low sex drive – as well as weight gain, decreased bone and muscle mass, and fatigue. You can add hair loss, emotional changes like depression and irritability, and negative changes to sleeping habits to the list too.
Low-T is a serious business. Yet, with testosterone levels peaking in early adulthood, and naturally decreasing after the age of 30, older men are more likely to have it. A simple blood test is all you need to diagnose it, and it can be treated with options such as injections, skin patches, and implanted pellets.

Introducing Low Testosterone

Fast cars, big muscles, an insatiable sexual appetite. The idea of testosterone tends to conjure up the most conventional images of masculinity. For many of us, the hormone is the essence of manliness, making us competitive, assertive, and dominant. And while this isn’t strictly true, it’s easy to see why having low testosterone might be a difficult reality for men to face. 

In this article, we’re going to take a look at what low testosterone – or Low-T, as we call it – is all about. We’re focusing here on the symptoms. However, when men are still expected to boast all of those traits above, Low-T can bring psychological challenges too. 

Let’s take a look at this tricky condition. While it can be difficult, don’t lose hope. There are plenty of treatments available. Importantly, though, remember that Low-T does not make you less of a man. 

What is Testosterone?

No man wants to face the idea that they have low levels of testosterone. However, it’s worth being clear on what testosterone actually does – not just what our society thinks it does. 

So, let’s forget about those big ideas of manliness for a moment. Medically speaking, testosterone is a hormone produced in the testicles – however, normal testosterone levels are regulated by the pituitary gland (which sits in the brain).

It’s helpful not because it makes you manly. Yet, it does play a role in certain features of men’s health and in many bodily functions we associate with being male: it helps develop muscle mass, it regulates fat distribution, it helps to maintain head, facial and body hair, and helps with keeping your energy levels stable.

It also controls some other really important stuff, like sperm production and having a healthy sex drive. It also helps your ability to achieve and maintain an erection. What it doesn’t seem to do, by the way, is affect your likelihood of contracting prostate cancer. 

So, yes, having a normal range of T levels is pretty important for your health as a man. It’s not that it makes you a man, though. In fact, women have testosterone too.

What is Low Testosterone?

So, that’s testosterone. While you may be starting to imagine some of the aspects of life that low testosterone affects, don’t get ahead of yourself just yet.

The first thing that needs to be said is that it is very normal to go through periods or moments of lower testosterone. Testosterone production varies across the day, and while you probably won’t experience any side effects of that fluctuation, it can skew results of any hormone tests you might have. 

Minor fluctuations aside, we call Low-T any chronic reduction in testosterone levels. This happens naturally as men age. It’s estimated that 2.1% of men over 40 have low-T, with the likelihood even higher for those who are overweight or over 80 years of age. 

However, it can be linked to pre-existing medical conditions such as diabetes, liver or kidney disease, or obesity. Damage to the pituitary gland can also suffer changes to their testosterone levels.

With the aging population in the UK, it’s likely that the number of men being diagnosed with low-T is only going to increase, so you are definitely not alone. Whatever the cause, if you notice your suffering from the symptoms of low testosterone, speak to a medical expert who can suggest treatments.

Low-T Symptoms: What Happens When a Man’s Testosterone is Low?

Now, let’s take a look at the symptoms of Low-T. These can be wide-ranging and can impact all aspects of your life, not just your sex life. There’s an emphasis on the ‘can’ – because you don’t need to present all of them to be suffering from the condition. 

If you think you may be suffering from low testosterone, you may have noticed one or several of the following symptoms.

Erectile Dysfunction (ED)

The link between erectile dysfunction and low testosterone is complex and isn’t completely understood. However, it’s thought that testosterone starts the chemical reactions within the brain and penis that result in getting, and maintaining, an erection. 

Therefore, abnormally low testosterone levels can mean difficulties in getting it up – and keeping it up – no matter how much you want to.

Sexual Dysfunction and Infertility

Sexual dysfunction symptoms such as a complete loss or significant reduction in your libido and smaller, softer, testicles can also be indicators of low testosterone. Sperm production is influenced by testosterone and other hormonal control, so it’s therefore a common problem among men with low-T.

Weight Gain and Loss of Muscle Mass

An increase in body fat, especially in the breast area, can signal a low testosterone level. While you may not lose physical strength, the mass of your muscles may reduce and you will probably feel more tired after exercise.

If you feel like your breasts are swelling, this might be a condition known as gynecomastia. While this is a symptom of testosterone deficiency, it is also affected by an imbalance of another hormone – estrogen –  too.

Decreased Bone Density

Testosterone promotes healthy bones. Low-T can increase the risk of developing osteoporosis, a condition characterised by a low bone mineral density. This can also be a condition associated with the normal ageing process, so it might not be a direct result of low testosterone levels.

Fatigue and Difficulty Sleeping

If you have previously suffered from insomnia or sleep apnea, you may find your sleep pattern worsens even further. If not, you may suddenly have difficulty sleeping well or you might feel tired even if you are well rested. You may not have the usual energy for daily tasks that you’re used to. A prolonged lack of interest in exercise or physical activity, especially in previously fit men, can be an indicator of low-T.

Hair Loss

Balding is a normal part of the ageing process for many men, due to male pattern baldness (MPB) on the scalp level caused by DHT. Hair loss can also be experienced due to low-T, especially when it happens as a general lack of hair all over the body. However, you can of course lose your hair due to MPB without having low-T – and you can have low-T without losing your hair. It depends on each individual.

Mood Swings and Depression

A lack of focus, depression and general irritability can be symptoms of low testosterone that affect your mental wellbeing. A prolonged period of low mood and lack of enthusiasm may be an indicator of hormonal imbalance too.

Importantly, if you are worrying that you have low-T, this might affect your mood too. That’s understandable. Talk to someone about it, or consult a doctor.

How to Know if You Have Low Testosterone

Luckily (sort of) the symptoms of low testosterone are fairly self-explanatory. Being aware of changes in your health and the low-T symptoms can lead to early diagnosis and the best chance to change your life.

If you notice you’re suffering from one or more of the above symptoms, a visit to the GP is in order. They will give you a physical check and refer you for a blood test to confirm the diagnosis. In medical terms, low testosterone can sometimes be referred to as hypogonadism, so don’t be alarmed if that term gets thrown into conversation. You’re talking about the same thing.

Identifying Healthy Testosterone Levels

Most of the research into low-T and it’s treatments has been done in the US, where an extensive 2017 study determined the benchmark testosterone levels considered “normal” for low-T testing (though age and sex dependent), as between 264 – 916 ng/dL (nanograms per decilitre). In the UK, levels of testosterone are often measured in nanomoles per litre of blood (nmol/L). 

A total testosterone (TT) level higher than 12 nmol/L or free testosterone (FT) level higher than 225 picomoles per litre (pmol/L) doesn’t require testosterone therapy. Levels from 8 to 12 nmol/L might require a trial of testosterone therapy for a minimum of 6 months – depending on symptoms. TT levels lower than 8 nmol/L or FT levels lower than 180 pmol/L (<0.180 nmol/L; based on 2 separate levels from 8am to 11am) usually requires testosterone therapy.

If you’re at all concerned about your testosterone levels, there’s really nothing to lose in getting checked for your levels. And it can open doors to effective treatment…

Treating Low Testosterone

If your test results confirm you are suffering from low-T, there are a range of lifestyle changes you can make, as well as treatment options, which can improve your quality of life and boost those all important testosterone levels.

Lifestyle Changes

To naturally improve your testosterone levels, or start reducing the symptoms of your low testosterone, it’s important to lead a healthy lifestyle. Exercising, keeping your weight in check and getting enough sleep will all help. Reducing stresses in your life can also boost testosterone levels, as cortisol (the stress hormone) can have a detrimental effect on testosterone.

In a recent study, it was found that many men suffering from low-T also had a zinc deficiency; the mineral being found to help regulate healthy testosterone levels. Eating foods rich in zinc, such as red meat, shellfish, eggs, legumes like chickpeas and beans, and dairy products may help naturally boost your testosterone levels.

Testosterone Therapy

If you’re a healthy weight, not overly stressed and otherwise in good shape, you may benefit from testosterone replacement therapy

Although there are a few different forms of testosterone replacement therapy (TRT) to treat the symptoms of low-T, their long-term effectiveness is still under review and results can vary from man to man. However, there are many reports of happy customers and success stories thanks to TRT – so it’s worth investigating. TRT options include:

Skin or Gum Patches

Applied every day, small testosterone patches allow the hormone to be absorbed through the skin. Due to the daily application, this treatment offers a fairly stable and consistent level of testosterone replacement.

Testosterone Gel

Similar to the patches, a pre-packaged dose of gel containing testosterone can be rubbed into skin on a daily basis. However, many men find this is a less convenient treatment compared with the patches, due to the hassle of application, and women and children will need to steer clear of your skin for a couple of hours after application to avoid transfer. 

The advantages of gel are that it is fast onset, and provides uniform and steady blood levels for 24 hours. The downsides are the possibility of inter-person transfer, plus the daily dosing and potential skin irritation at the site of application. 


Administered periodically (can be every week or month), injections of testosterone are another form of treatment. But, be aware; the injections can be painful and due to the time lapse between doses, testosterone levels can peak and trough, and blood level fluctuations may prove to be difficult to manage.


A slightly more invasive option, but small pellets containing testosterone can be implanted, usually into the hip or buttock, which slowly release the hormone into your body. The pellets are around the size of a grain of rice and are replaced every few months. 

In the UK, the gel application and injections are the most common TRT treatments available, but a specialist will be able to suggest the most suitable treatment for you. Whilst testosterone replacement therapy may well help reduce your current symptoms, there is no research to suggest the treatment will reverse the effects you’ve already experienced, so be prepared to adopt a long-term treatment plan.

Key Takeaways…

In short, if you’re suffering from the symptoms of low testosterone, you are not alone and there is nothing to be ashamed of. There’s no need to put off investigating further; a simple blood test is all you need, and the positive effects of treatment could change your life.

While we've ensured that everything you read on the Health Centre is medically reviewed and approved, information presented here is not intended to be a substitute for professional medical advice, diagnosis, or treatment. It should never be relied upon for specific medical advice. If you have any questions or concerns, please talk to your doctor.

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