Any man scrolling down the list of symptoms of low testosterone on the NHS website will quickly notice a problem.
Symptoms include fatigue, depression, anxiety, irritability, mood changes, low libido, poor fertility, erectile dysfunction, reduced exercise performance, loss of strength, night sweats, poor concentration, memory problems, reduced shaving frequency and hair loss.
See the problem now? There is not a single man on Earth who doesn’t suffer from at least one of those symptoms.
And these extremely vague and confusingly broad symptoms overlap with those of many other health issues, such as obesity, depression and stress.
Of course, given the pivotal importance of testosterone to a man’s physical and mental health, this diverse range of symptoms is logical.
Testosterone, which is produced in the testes and regulated by the hypothalamus and pituitary gland, is the primary sex hormone in males.
It fuels everything from a man’s muscle growth, bone strength, red blood cell production, sperm production, heart health and sexual performance to his mental focus, memory performance and energy levels.
So, if a man’s testosterone levels drop, it is inevitable that the effects on his health can be wide-ranging.
- Read more: Men are facing a testosterone crisis – these 15 fixes will turbocharge the essential hormone
Do I have low testosterone?
The big issue is that this broad list of symptoms makes a clear diagnosis difficult. It means it is dangerously easy for healthy men to wrongly fret about low testosterone, based on vague symptoms.
And it also makes it easy for doctors to miss genuine cases of low testosterone when men turn up with other health problems, such as depression, infertility issues or osteoporosis.
“A big challenge for GPs is diagnosing the men with real [testosterone problems],” says Dr Channa Jayasena, a specialist in reproductive endocrinology at Imperial College London.
As a result of this confusion, many men who do not have low testosterone, but convince themselves that they have, make the dangerous mistake of seeking private or illegal testosterone treatment.
This only damages their hormonal health, as the body senses the excess hormone and switches off their natural testosterone production.
The UK has witnessed a huge 90% increase in testosterone prescriptions. “That's a road to ruin,” warns Professor Richard Sharpe, of the MRC Centre For Reproductive Health at The University of Edinburgh.
“If you (wrongly) start taking exogenous testosterone, that suppresses your endogenous testosterone, which means that your sperm production process will suffer.”
The results can be extremely serious, including infertility, shrunken testicles and heart problems: three symptoms no man dreams about.
However, the flip side is that many men with genuinely low testosterone can struggle to get diagnosed.
Often, doctors assume from their patient’s vague symptoms that they are suffering from depression or stress, without ever checking their testosterone levels.
“The problem we have nowadays is that as soon as a patient starts to mention those symptoms, the GP’s hand is going for the prescription pad for an antidepressant,” says Professor Hackett, consultant in urology at Spire Little Aston Hospital and lead author of the British Society for Sexual Medicine’s Guidelines on Male Adult Testosterone Deficiency.
Why does my hormonal health matter?
No wonder there is so much confusion, anxiety and misinformation among men.
The only solution to this problem is self-education. Knowing what signs to look out for can guide you through these stormy hormonal waters.
And this issue matters, because low testosterone is linked to serious health issues, including high cholesterol, diabetes, anaemia, obesity, osteoporosis, heart disease, erectile issues and infertility – even a 40% higher risk of early death.
And research suggests modern men are facing a disturbing global decline in their hormonal health, with one major study reporting a “substantial” drop in testosterone levels since 1987, at a rate of 1% each year.
Research suggests about 2.1% of men have medically low testosterone and require prescribed testosterone injections or transdermal patches.
But around 20% of men have sub-optimal testosterone levels, which can usually be reversed through healthy lifestyle change.
A medical diagnosis of low testosterone is made through a combination of symptoms and blood tests.
A ‘normal’ testosterone level typically ranges from 8-10 to 30-31 nmol/L (nanomoles per litre) of blood.
However, it is usually the symptoms that provide the trigger for the blood test. But with so many vague and confusing symptoms, which ones should men pay most attention to?
What are the 3 big symptoms?
Fortunately, a major research paper known as the European Male Ageing Study has injected much-needed clarity into the discussion.
The study revealed that the three most powerful clues to low testosterone are loss of morning and evening erections, low libido and erectile dysfunction.
“The study took 3,000 men and asked them questions about any symptom under the sun,” says Dr Jayasena.
“And hardly any symptoms were related to testosterone - apart from those three. There are many reasons why you could be tired, or not feel quite yourself.
"However, the risk of having low libido, loss of morning erections and erectile dysfunction rose below a certain threshold of testosterone.”
This makes scientific sense. Testosterone is a sex hormone, so it is no surprise that these overtly sexual symptoms offer the most specific clues to low testosterone.
Loss of morning and evening erections
Men still get squeamish about discussing their sexual deficiencies, but a loss of spontaneous erections in the morning or evening is a very strong indicator of low testosterone.
“Early morning erections, in particular, are the best predictor,” says Professor Hackett.
“What goes on in a sexual relationship can be affected by a lot of things – the emotion, the relationship, and whether the partner is enjoying it.
“But with morning erections, this is nature's way of keeping the (penis) tissues perfused. So morning and evening erections should exist even in a man who isn't in a sexual relationship, because it's a physiological protective mechanism.
“Without this, when we send soldiers abroad for 12 months, they'd all come back impotent, because they can’t have sex.
“Morning erections are how the body preserves sexual function, even when sex is not possible. And testosterone is usually highest in the morning, which is why a loss of morning erections, in particular, is a very strong sign of low testosterone.”
Erectile dysfunction
Erectile dysfunction – when a man finds it difficult to get or maintain an erection at any time of day, not only in the morning or evening – is another warning sign of low testosterone.
“Testosterone has important actions on the system that operates the penis and allows erections,” says Dr Jayasena. “So when you lose testosterone, you lose that response.”
Professor Hackett is concerned that a reluctance among men to talk about erections, and among doctors to ask questions about them, is exacerbating the issue.
“Even in this day and age, doctors are still reluctant to ask about erections,” he says. “I can’t believe that almost 30 years since Viagra was thought of, we're still not able to do this.”
Low libido
A dip in sexual desire is the third of the big clues to low testosterone. “Testosterone has actions in the brain for controlling libido in men, which is a very mysterious, elusive biological process,” says Dr Jayasena.
“But we know testosterone is a key cog in that machine, not just for making the penis work, but also for your brain and for somehow, mysteriously, wanting to have sex.”
This could be a symptom in itself, or somehow related to erectile issues.
“A lack of libido can occur as the primary problem, and therefore you don't have sex or want to have sex because you've lost your libido,” says Professor Hackett.
“But if you've lost your erections, you lose the motivation to have sex because you're not good at it.
“If you tried to hit a golf ball and you kept missing, and your neighbour asked if you would like to play 18 holes, you'll very quickly find excuses to get out of it.”
Next steps
All of the symptoms of low testosterone listed by the NHS, from depression to night sweats, remain valid.
It is just that they are much more difficult to link to low testosterone. The three symptoms above, however, are the most likely sign of low testosterone and therefore represent the big three warning signs to look out for.
If you suffer from these sexual symptoms, it is time to speak to your doctor. “I think that there should be an open ability to have an open conversation with your doctor, just like thinking about cholesterol, and to say, well, I'm not feeling so great, shall we get my testosterone checked?” says Dr Jayasena.
If you are one of the 2.1% of men who have medically low testosterone, you may be prescribed testosterone injections or patches.
But if you are among the 20% of men who have sub-optimal testosterone levels – low, but not low enough to warrant treatment – scientific evidence confirms that you can reverse the trend with positive lifestyle changes.
Interventions include losing weight, performing resistance training, eating more fish and green leafy veg, cutting down on alcohol and taking vitamin D.
One study found that overweight men who lose weight cut their chances of low testosterone by 50%. So there is plenty of hope for men with low testosterone.
“To some extent, you as a man can minimise the chances of these things happening,” insists Dr Jayasena.
