Some men develop depression, loss of sex drive, erectile dysfunction, and other physical and emotional symptoms when they reach their late 40s to early 50s.
Other symptoms common in men this age are:
These symptoms can interfere with everyday life and happiness, so it's important to find the underlying cause and work out what can be done to resolve it.
The "male menopause" (sometimes called the andropause) is an unhelpful term sometimes used in the media.
This label is misleading because it suggests the symptoms are the result of a sudden drop in testosterone in middle age, similar to what occurs in the female menopause. This is not true.
Although testosterone levels fall as men age, the decline is steady at less than 2% a year from around the age of 30 to 40, and this is unlikely to cause any problems in itself.
A testosterone deficiency that develops later in life, also known as late-onset hypogonadism, can sometimes be responsible for these symptoms, but in many cases the symptoms are nothing to do with hormones.
Lifestyle factors or psychological problems are often responsible for many of these symptoms.
There are also physical causes of erectile dysfunction, such as changes in the blood vessels, which may happen alongside any psychological cause.
Psychological problems are typically brought on by work or relationship issues, divorce, money problems or worrying about ageing parents.
A "midlife crisis" can also be responsible. This can happen when men think they have reached life's halfway stage.
Anxieties over what they have accomplished so far, either in their job or personal life, can lead to a period of depression.
Other possible causes of the "male menopause" include:
In some cases, where lifestyle or psychological problems do not seem to be responsible, the symptoms of the "male menopause" may be the result of hypogonadism, where the testes produce few or no hormones.
Hypogonadism is sometimes present from birth, which can cause symptoms like delayed puberty and small testes.
This is known as late-onset hypogonadism and can cause the "male menopause" symptoms.
But this is an uncommon and specific medical condition that's not a normal part of ageing.
A diagnosis of late-onset hypogonadism can usually be made based on your symptoms and the results of blood tests used to measure your testosterone levels.
If you're experiencing any of these symptoms, see your GP. They'll ask about your work and personal life to see if your symptoms may be caused by a mental health issue, such as stress or anxiety.
If stress or anxiety are affecting you, you may benefit from medication or a talking therapy, such as cognitive behavioural therapy (CBT).
Exercise and relaxation can also help.
Your GP may also order a blood test to measure your testosterone levels.
If the results suggest you have a testosterone deficiency, you may be referred to an endocrinologist, a specialist in hormone problems.
If the specialist confirms this diagnosis, you may be offered testosterone replacement to correct the hormone deficiency, which should relieve your symptoms.
This treatment may be either: