The causes and symptoms of low testosterone in men and how it is treated

Testosterone is a male sex hormone, which is linked to male hair growth, muscle mass and sperm production, among other functions. Testosterone levels tend to decrease in later life. Some people have described a "male menopause" caused by low testosterone, or hypogonadism, happening in later life. This can lead to symptoms including low bone density, with increased risk of fracture, and decreased sexual function. Low testosterone can also be caused by several medical conditions in younger men as well as older men.

Here's everything you need to know about the symptoms, causes and treatments for low testosterone in men.

What causes low testosterone in older men?

Testosterone levels increase during puberty and then decrease in later life as part of the ageing process. However, some conditions are linked to low testosterone, such as high blood pressure, high cholesterol, diabetes, obesity, HIV and AIDS and long-term opioid use, according to the Urology Care Foundation.

What causes low testosterone in younger men?

There are several conditions that can lead to low testosterone in younger men. These include pituitary disorders, which affect the release of hormones from the pituitary gland in the brain. Disruptions to the pituitary gland, such as a tumour, can cause hormone imbalances including hypogonadism. Inflammation near the pituitary gland can also cause these hormonal changes.

What are the symptoms of low testosterone in men?

Erectile dysfunction, infertility, fatigue, loss of muscle mass, increased body fat, back pain, low sperm count and the development of larger volumes of breast tissue are all symptoms of low testosterone in men, according to Men's Hormonal Health.

Is the male menopause a real thing?

There a collection of symptoms that men in their 40s and 50s often develop, including: mood swings, irritability, loss of muscle mass, fat redistribution, fatigue, insomnia, poor concentration and memory loss, according to the NHS. Unlike the female menopause, these symptoms often build gradually, rather than relatively suddenly in a matter of a few years.

What are the treatments for low testosterone?

Testosterone gels, such as Testogel or AndroGel, are used for men who generate no testosterone or low levels of testosterone. These gels are typically applied to the upper arms and back, and in some cases the abdomen. They can cause problems in children who are exposed to the gel by touching someone who is using the treatments.

Are testosterone treatments good or bad for heart health?

A study of 138 men, about half of whom were given the testosterone gel and half who were given a placebo gel, found that the testosterone gel actually led to more calcified plaques in the arteries. Hard plaques in the arteries are a risk factor for heart problems, suggesting that the testosterone gel was in fact worsening older men's heart health rather than improving it. Artery plaques can increase risk of stroke and heart attack.

The results are at best mixed, and will require larger studies to determine the effects of testosterone gels on heart health. However, some studies have found that testosterone treatments – administered orally, in gel form or by injection – can decrease the risk of cardiovascular problems.

Are testosterone treatments good for treating anaemia?

Anaemia is a lack of red blood cells, and can lead to symptoms such as fatigue. A study on older men with mild anaemia that couldn't be attributed to any other health problems found that testosterone gels improved their red blood cell count more than a placebo gel did.

Can testosterone treatments improve memory?

Memory and cognitive function declines with age. A recent study investigated a link between testosterone and brain health of older men with low testosterone. It found that a year of testosterone gel treatment was no better at improving memory or cognitive functions in the men compared with a placebo gel.

Can testosterone treatments improve cognitive function?

Cognitive decline in older men is common, but a study of 493 older men with age-associated cognitive problems found no concrete evidence that a testosterone gel had any better results than placebo after a year.

Do testosterone treatments help increase bone density?

Testosterone gel does appear to be effective in increasing bone density in older men, according to a recent study. Spine and hip bone density were both significantly increased after a year of treatment with the testosterone gel compared with a placebo gel. Increased bone density is linked to a lower risk of fracture, and so could potentially improve older men's quality of life, although further research is needed to determine the benefits of the gel.