Professor Matthew Kiernan

And if they start to get...

are closed off slightly, that can be the cause of the presentation.

In other words, not enough blood flowing.

Not enough blood flowing up.

And we use, again, about a 70% marker.

So if it's less than 70% flow, that's significant.

Right.

But now with Doppler, with technology, we can actually trace that up and we can go and now look at the blood vessels, the middle cerebral artery, posterior cerebral artery, which form a sort of circle inside the brain called the circle of Willis.

So we can study that now through ultrasound.

And again, we can get some marker about blood flow.

Right.

All of those factors, but definitely smoking would have been probably the most common cause.

And I've seen that evolution now.

Like in the 90s, we were seeing a lot of carotid artery, we use the word stenosis.

It's less common now.

People don't smoke as much as they used to.

It's rare that you see smokers now.

You've mentioned then cholesterol, so understanding LDL in particular, more than about 4.5 or more than two, but the total cholesterol of more than 4.5 is significant.

blood sugar levels, and obviously, you know, your body mass index.

That's a new thing, isn't it?