Hormonal & Metabolic

Low testosterone symptoms: when should men get checked?

Medically reviewed by Dr Martin Galy, Co-Founder & Director of Wellness & Longevity · Published 1 November 2026 · Last reviewed 1 November 2026

Quick answer: The most specific low testosterone symptoms are sexual: fewer morning erections, lower sex drive and erection problems. Tiredness, low mood, poor sleep and losing muscle can also occur, but have many other causes. Men with symptoms lasting several weeks should get checked, with a doctor's assessment and two morning blood tests.

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November is Movember, a month of awareness about men's health, and International Men's Day falls on 19 November. A good time to clear up a common myth: that men don't have hormone changes. They do, and those changes can affect both wellbeing and physical health.

What are the symptoms of low testosterone?

Low testosterone symptoms fall into four groups. The British Society for Sexual Medicine (BSSM) and the NHS list the following [1][3]:

Sexual: lower sex drive, erection problems (erectile dysfunction), fewer or no morning erections, fewer sexual thoughts.
Physical: tiredness, poor sleep, loss of muscle and strength, more fat around the middle, breast tissue swelling (gynaecomastia), hot flushes or sweats, reduced body hair.
Mood and thinking: irritability, low mood, reduced wellbeing, poor concentration and memory.
Metabolic: testosterone deficiency is linked with obesity, insulin resistance (when the body responds poorly to insulin) and type 2 diabetes.

Having one or two of these does not always mean testosterone is low.

What are the first signs of low testosterone?

The clearest early signs are sexual. The European Male Ageing Study, which assessed 3,369 men aged 40 to 79 across eight European centres, found that only three symptoms were consistently linked with low testosterone: poor morning erections, low sexual desire and erectile dysfunction [2].

Symptom	How strongly it points to low testosterone
Low sex drive, fewer morning erections, erection problems	The most specific signs [2]
Tiredness, low mood, struggling with vigorous exercise	Linked, but much less specific [2]
Poor sleep, weight gain, poor concentration	Common, with many possible causes [1][3]

Is low testosterone just ageing?

No. Testosterone does fall naturally with age, but slowly. A decline of about 1% a year from around the age of 30 to 40 is commonly accepted as natural, and in Dr Galy's clinical experience this gradual fall is unlikely to cause sudden-onset problems. "Male menopause" may be an unhelpful term, because men do not have the sudden hormone drop, and sudden appearance of symptoms, that most women have at menopause [1]. In Dr Galy's experience, some men start from a lower peak in their youth, so the same natural decline leaves them with lower levels than others in their 40s and 50s, whilst other men's testosterone falls faster because of environmental and lifestyle factors.

When should I get my testosterone checked?

Get checked if symptoms have lasted several weeks, keep coming back or are affecting your relationships, work or exercise. The BSSM recommends testing [3]:

all men with erectile dysfunction, loss of spontaneous erections or reduced sexual desire;
all men with type 2 diabetes;
all men with a BMI over 30;
all men with a waist over 102 cm.

Two signs are worth raising promptly, even if you feel well otherwise:

Erection problems or losing morning erections. The BSSM describes these as strong markers of coronary heart disease risk [3]. The NHS notes that recurring erection problems can signal treatable conditions such as high blood pressure, high cholesterol or diabetes [5].
Being told you stop breathing, gasp or choke in your sleep. These can be signs of obstructive sleep apnoea, which can be serious if not diagnosed and treated [6].

The Endocrine Society advises against routinely screening all men; testing makes sense when there are symptoms [4]. Important: if low mood ever includes thoughts of harming yourself, contact your local emergency services straight away, rather than only getting your levels checked.

How is testosterone tested?

Testosterone is tested with a morning blood sample, repeated, because levels change through the day, after meals and during illness.

The BSSM guideline recommends testing between 7am and 11am on at least two occasions, ideally about four weeks apart, and avoiding testing during an acute illness [3]. Fasting is ideal: in healthy volunteers, a glucose drink lowered testosterone by about 25% [3]. The Endocrine Society likewise recommends confirming the diagnosis with a repeat morning fasting test, and diagnosing deficiency only when symptoms are present and levels are consistently low [4].

What counts as low? The BSSM generally uses a total testosterone below 12 nmol/L on two morning tests in a man with symptoms [3]. If testosterone is low, tests for LH and FSH (pituitary hormones that signal the testes) help show whether the cause lies in the testes or the pituitary gland [3][4].

What else can cause the same symptoms?

Many common conditions mimic low testosterone:

Stress, anxiety and depression, often tied to work, money or relationships [1].
Lifestyle: poor sleep, poor diet, little exercise, heavy drinking and smoking [1].
Obstructive sleep apnoea: loud snoring, waking often, daytime tiredness and morning headaches [6].
An underactive thyroid: tiredness, weight gain, low mood and poor concentration, checked with TSH and T4 blood tests [7].
Heart and metabolic health: high blood pressure, high cholesterol and diabetes can cause erection problems [5].
Some medicines, including long-term opioids [3][5].

A doctor-led assessment looks at all of these together. At 23MD this can sit alongside our metabolic health assessment.

The 23MD view

"Men often arrive having read about testosterone and expecting a single number to explain how they feel. We start with the whole story: sleep, stress, alcohol, weight and sexual health. Our first consultation lasts 45 to 60 minutes, so there is time to decide which tests are actually useful and to time them properly. Hormones are one part of the picture, and any options are discussed only once we understand the cause." — Dr Martin Galy

You can read more about how we assess low testosterone symptoms at 23MD and our wider wellness and longevity care.

Who this is for, and who it isn't for

For men who have noticed lower sex drive, fewer morning erections or erection problems for several weeks.
For men with type 2 diabetes, a larger waist or poor sleep who want a joined-up check of hormones and metabolic health.
Not for anyone with chest pain, sudden breathlessness or thoughts of self-harm: contact emergency services.
Not for men looking for a prescription without an assessment. History and properly timed tests come first.

Frequently asked questions

What is the most common symptom of low testosterone?

Low sex drive and fewer morning erections are the symptoms most specifically linked with low testosterone in large studies [2]. Tiredness is common too, but has many other causes [1].

At what age does testosterone start to drop?

The NHS describes testosterone falling by about 1% a year from around 30 to 40 [1]. This slow fall alone is unlikely to cause symptoms [1].

Can I test my testosterone at home?

A single sample, especially taken later in the day, can be misleading. Guidelines recommend two morning samples interpreted by a doctor with your symptoms [3][4].

Can low testosterone affect the heart?

Low testosterone is linked with type 2 diabetes and obesity, and erection problems are recognised markers of heart disease risk [3].

Want to get your questions in order before you see a doctor? Our BHRT Expert explains common hormone symptoms and helps you prepare questions for a consultation. It gives general information only: it doesn't diagnose and doesn't replace an assessment with a doctor.

Talk to a 23MD doctor

Suitability and results vary, and your doctor will discuss the benefits and risks of any option with you. Book a men's health consultation with Dr Galy and our team.