Written by Francesca Steyn, NMC-registered fertility practitioner
It is Sexual Health Week, and for most men sexual health still means one thing: getting checked for STIs. That matters, but men's sexual health is a much wider picture, and the parts that get left out are often the ones men have questions about. This is a plain guide to what it covers, and which test answers which question.
Brook run Sexual Health Week in the UK, and this year's campaign (14 to 20 September, with Movember) is themed around connection. That feels right. Most of what goes unaddressed in men's sexual health goes unaddressed because nobody brings it up.
What sexual health actually covers
The World Health Organisation has defined sexual health since 2006 as "a state of physical, emotional, mental and social well-being in relation to sexuality", and is explicit that it is "not merely the absence of disease, dysfunction or infirmity".
In practice, for men, that includes:
- Infection status, which is the STI screen everyone thinks of
- Fertility, meaning whether your sperm can do the job if and when you want it to
- Hormones, particularly testosterone, which affects energy, mood, libido and sperm production
- Erectile and ejaculatory function
- Contraception, including vasectomy and what it does and does not do
- The emotional side, which is how you feel about any of the above and how you talk about it
Only the first of those is routinely offered. The rest you generally have to ask for.
Men's sexual health stops at STIs, and it shouldn't
There is a good reason STI testing dominates. It is free, it is quick, the pathway is clear, and it works: UKHSA data published in June 2026 showed new STI diagnoses in England fell 8.3% across 2025. Sexual health services do their job well.
The gap is everything either side of it. Take fertility. The HFEA's position is that for around half of heterosexual couples having problems conceiving, the cause is sperm-related. Yet men typically get a standard semen analysis and little else. As one specialist put it writing for the HFEA, a lot of couples end up labelled "unexplained" when the more accurate word is "un-investigated". The NHS says the cause cannot be identified in around 1 in 4 UK cases.
Or take erections. The NHS describes erectile dysfunction as very common, particularly over 40, and notes that persistent problems can point to high blood pressure, high cholesterol, diabetes, anxiety or a hormone issue. That makes it worth mentioning to a GP rather than working around.
England published its first ever Men's Health Strategy in November 2025, largely on the back of men dying nearly four years earlier than women and being less likely to ask for help. Sexual health is one of the easier places to start closing that gap, because the tests already exist. We have written before about why male fertility still gets overlooked.
An STI screen and a sperm test answer different questions
This is the single most useful thing to understand, and it trips up a lot of people.
An STI screen answers: have I picked up an infection? It usually covers chlamydia, gonorrhoea, HIV and syphilis, through a urine sample, swabs and a blood test. It is free on the NHS, and it tells you nothing about your fertility.
A semen analysis answers: how is my sperm doing? It looks at volume, concentration, total count, motility (how well sperm move) and morphology (their shape), measured against World Health Organisation reference values. It tells you nothing about infection.
You can have a completely clear STI screen and a low sperm count. You can have excellent sperm parameters and an untreated infection. A clear STI screen is genuinely good news, but it is not a fertility result. That is a separate test.
A hormone profile answers a third question: is the system driving sperm production working? That is testosterone, FSH, LH and related markers. It is the test that explains a lot of borderline semen results, and it is the one most often skipped.
What a vasectomy changes, and what it does not
Vasectomy is one of the most misunderstood areas of men's sexual health, so here is what actually happens.
What it changes: it stops sperm being ejaculated. That is it. NHS guidance is that you keep using another form of contraception until a doctor confirms it has worked, which usually takes around 12 weeks and is confirmed by a semen test, not by time passing.
What it does not change: the NHS is clear that a vasectomy does not stop you getting or passing on STIs, so condoms are still the only thing doing that job, and that there is no evidence it affects long-term sexual performance or enjoyment. Your testicles carry on producing testosterone exactly as before, so sex drive and erections are unaffected. Ejaculation looks and feels the same too, because sperm make up only a few per cent of semen volume.
The one genuine caveat is permanence. Reversal is possible but is not usually available on the NHS and does not always work, so a vasectomy is best treated as a permanent decision.
How to bring it up with your partner
If you are trying for a baby, or thinking about it, the conversation tends to stall because it feels like an accusation in either direction. Two things help.
Lead with the test, not the theory. "I want to get checked so we know" lands very differently from "it might be me". You are proposing information, not blame.
Go first. Fertility investigation usually starts with the woman, which is a habit rather than a rule. A semen analysis is quick, non-invasive and far simpler than most of what she may be asked to do. Volunteering for it takes the weight off the conversation. Pick a dull moment for it: on a walk, in the car, doing the washing up.
What this means in practice
If you are sexually active and have had a change of partner, get an STI screen. It is free and it is fast, and Sexual Health Week is as good a prompt as any.
If you are thinking about children in the next few years, a semen analysis gives you a baseline while you still have time to act on it, and why sperm health matters covers the reasoning. Sperm regenerate on roughly a three month cycle, so results are a snapshot you can influence, not a verdict.
If you have been trying for 12 months or more, NICE guidance (NG257) says both partners should be offered further clinical assessment and investigation at that point, and earlier where there is a known or suspected cause. A semen analysis plus a hormone profile gives a clinician far more to work with than a semen analysis alone.
If you have had a vasectomy and were never cleared, or that was years ago and you want to confirm nothing has changed, a semen test is how you check.
Malebox exists for the last three of those. We post a kit, a lab analyses it against World Health Organisation reference values, and a fertility nurse registered with the Nursing and Midwifery Council (NMC) talks you through what the numbers mean on a video call. The sperm test starts at £180, or £240 with the consultation, and £320 for the version that adds a full hormone profile. If you just need an STI screen, your local sexual health clinic is the right place and it will not cost you anything.
Frequently Asked Questions
Does an STI test check your fertility?
No. An STI screen looks for infections such as chlamydia, gonorrhoea, HIV and syphilis. It does not measure sperm count, motility or morphology. Fertility is assessed by a semen analysis, which is a completely separate test.
What does a semen analysis actually measure?
Semen volume, sperm concentration, total sperm count, motility (how well sperm swim) and morphology (their shape). Results are compared against World Health Organisation reference values to show where you sit.
Does a vasectomy affect testosterone or sex drive?
No. A vasectomy blocks sperm from reaching the semen. Your testicles keep producing testosterone as before, and the NHS says there is no evidence a vasectomy affects long-term sexual performance or enjoyment.
How do I know my vasectomy worked?
Only a semen test can confirm it. The NHS advises using another form of contraception until a doctor confirms the vasectomy has been successful, which usually takes around 12 weeks after the procedure.
When should a man get his fertility checked?
NICE guidance says both partners should be offered assessment after 12 months of trying, or earlier if there is a known or suspected cause. Many men test sooner simply to have a baseline before they start trying.
Sexual health is not one test, and it is not one conversation. If this week does anything, it is worth using it as the nudge to work out which question you actually want answered, and then booking the test that answers it.
Francesca Steyn is an NMC-registered fertility practitioner with over 20 years in reproductive health. She has served on the NICE guideline committee and the HFEA legislative reform group.
