Dr Norman Swan, Physician and Journalist

The COVID test is usually what’s called a nasopharyngeal swab, which means that they put a swab, a fairly long swab, into your nose, right to the back of your nose, and it’s gotta be wriggled around, to pick up enough tissue and secretions from the back of your nose. It is a bit eye watering. It shouldn’t be painful, but it is eye watering. If your eyes don’t water, it may not have gone back far enough.

Then, you remove it, and you put it into the medium, which is a little tube, which keeps the virus growing, or it doesn’t kill the virus, until it gets to the lab. That’s the commonest way.

Sometimes, you’ll see people doing throat swabs, but mostly, people are doing nasopharyngeal. So, they’re picking it up in the nose, and at the back of the throat, at the top of the back of the throat. And that’s probably the easiest way to pick up the virus. But even with that, if it’s early on in the infection, it may not pick up enough virus to register as positive. So you, you know, if you’ve got, for example, loss of taste, or loss of smell, and you’ve got a negative test, you’ve really almost certainly gotta go back for a second test, which will almost certainly be positive, once you’ve had that.