When you are at the doctor's and about to have your blood pressure taken, you may be worried that your anxiety will cause a spike, suggesting to the doctor that you have hypertension - aka high blood pressure. But there is a tell-tale sign that they use to know if it's really of concern, or you're just nervous.

Taking to TikTok to put minds at ease, Dr Martin aka @drmartinmckee has warned patients that there is no need to worry about this at all. With one of his viewers asking how experts can tell the difference between high blood pressure and whitecoat syndrome, Martin explains: "I’m a doctor. I’m a GP in Scotland and I do videos here about general practice on healthcare. This is a really, really good question.

"So we can normally tell the difference between white coat syndrome, which is when your blood pressure rises when you’re in a healthcare setting but it doesn’t rise when you’re not in a healthcare setting. And hypertension or high blood pressure, based on the numbers and also home readings."

He further explains: "We know that in hospital your blood pressure is higher than when you're in a GP surgery with a doctor and your blood pressure is lower with a nurse in a GP surgery than it is with a GP. And what we can see is the top number of your blood pressure, which we call the systolic blood pressure, so that's the blood pressure when your heart is actively pumping, tends to be disproportionately higher than the bottom number which is the diastolic blood pressure - when your heart is relaxing and filling up with blood.

"So if we see a big discrepancy between the top number and the bottom number, that might give us an idea that you’re having a white coat syndrome, but we wouldn’t rely on that in isolation". If a doctor suspects you have "true high blood pressure", what they will often do is arrange you to take away a blood pressure monitor so you can use it at home - and you'll be taught how to do this.

Dr Martin says you will "record your blood pressure at home normally for a week so we get several readings and we average those readings. If that makes the threshold for a diagnosis of high blood pressure average - after the average has been taken at home - then we can with confidence say, well it looks like you have high blood pressure and that’s a way of excluding white coat syndrome".

According to Blood Pressure UK, "most people are more tense than usual in medical settings and might not even realise it. So your blood pressure can be raised even if you don’t feel stressed".

Stating that it's also known as the white coat effect and is "fairly common", the term ‘white coat’ of course refers to the white coats traditionally worn by doctors. They add that "on average, the top (systolic) number tends to be about 10mmHg higher in a clinic than at home. The bottom numbers tends to be about 5mmHg. Some people’s blood pressure will be affected more than others, and if you feel very worried or stressed it could be raised by as much as 30mmHg."

What are the symptoms of high blood pressure?

High blood pressure does not usually cause any symptoms and many people have it without realising it.

Rarely, high blood pressure can cause symptoms such as:

• headaches
• blurred vision
• chest pain

But the only way to find out if you have high blood pressure is to get your blood pressure checked.