What a clean test actually covers (and what it doesn't)

"He's clean, he showed me the text."

Great. A text that says "all clear" is a good sign. But all clear from what, exactly? Because "clean" is doing a lot of lifting in that sentence, and it's worth knowing what's actually underneath it.

This is what a standard test covers, what it doesn't, and the small print that makes "I tested last week" mean more or less than it sounds.

The big four

Every free postal kit in the UK, and every standard clinic visit, checks the same four things.

Chlamydia. The most common one. Usually no symptoms. A wee sample or a swab. Cleared with a week of tablets.

Gonorrhoea. Same sample as chlamydia, often no symptoms either, particularly in the throat. Cleared with one injection.

HIV. A blood test. Finger prick into a little tube for a postal kit, or a proper draw at a clinic. Not curable, but treatable to the point where it can't be passed on.

Syphilis. Same blood sample. Making a bit of a comeback. Cleared with penicillin.

That's it. That's what "all clear" means on almost every result you'll ever be shown. Four infections, one wee, one finger prick.

Some services add more depending on how you answer their questions. Hepatitis B and C if you tick certain boxes. Trichomoniasis in some clinics. But the four above are the floor, and for most people the four above are the whole test.

What it doesn't cover

Here's where "clean" gets slippery.

Herpes. No routine test. They can swab a sore if you've got one, but there's no "have I got herpes" check on a standard kit. The blood tests exist but they're vague, they can't tell you where or when, and the NHS doesn't bother with them for people without symptoms. Which means every clean test you've ever seen, including yours, says nothing about herpes.

HPV. No test for men, full stop. For women it's picked up through cervical screening, which is a separate thing entirely. Most people who've had sex catch some type at some point and clear it without noticing. The vaccine covers the nasty ones. Not on the kit.

Mycoplasma genitalium. A newer one, only tested if you've got symptoms. Not routine.

Anything in a place you didn't swab. Which brings us to the bit everyone gets wrong.

Your throat is a separate test

Chlamydia and gonorrhoea can live in your throat. And in your bum. They don't announce themselves there. And a wee sample doesn't find them, because a wee sample is testing a different part of you.

If you've given oral (so, everyone), you need a throat swab to know your throat's clear. Postal kits will usually include one if you say yes to the oral question, and clinics will do it if you ask. Loads of people skip it out of embarrassment or because they didn't know, and then wave around a clean result that never looked at their mouth.

"All clear" means all clear where they looked. Nobody looked in your throat unless you told them to.

There's a whole post on oral if you want the grown-up version.

The timing catch

A test tells you about the past, up to a point. Each infection has a window: the gap between catching it and a test being able to see it.

Chlamydia and gonorrhoea, two weeks. HIV, six to seven weeks on a lab blood test, twelve on a home finger-prick. Syphilis, twelve weeks.

So a test taken the Monday after a big weekend is clean for everything that happened before that weekend. The weekend itself isn't in the picture yet. The post on how often to test has the full calendar.

And obviously, a test covers nothing that's happened since. A three-month-old result from a man who's had a busy summer is a historical document.

So what does "clean" actually mean?

It means: on this date, someone did a wee and a finger prick, and it found none of the big four in the places they looked, for anything that happened long enough ago to show up.

That's genuinely useful. It's the best information anyone has short of a crystal ball. It rules out the common, curable stuff, it catches the serious stuff early, and it means the person did the responsible thing.

It's not a certificate. It doesn't cover herpes, doesn't cover HPV, doesn't cover last night. Condoms still exist and are still good.

What the green tick shows

In the app, a green tick means someone uploaded a clean result, the name matched their ID, and the test is less than ninety days old. Underneath the tick you can see what the test covered, so if his kit did the four plus a throat swab, you'll see that. If it was just the four, you'll see that too.

No guesswork about what "clean" meant. It's written down.

Get your green tick, and say yes to the throat swab.