It is known as the silent killer, and can lead to a heart attack, a stroke or heart disease.

Eastern Daily Press: John Atkins, from Blofield, said he found out he had high blood pressure by accident. Photo: Norfolk County CouncilJohn Atkins, from Blofield, said he found out he had high blood pressure by accident. Photo: Norfolk County Council (Image: Archant)

But despite the risks, it is estimated that one in six adults in Norfolk are completely unaware they have high blood pressure.

Norfolk County Council's public health team is now urging people to get their blood pressure checked as part of an awareness campaign launched today.

The council said any adult who has not had their blood pressure taken in the past five years should visit a participating pharmacy to get it assessed.

Margaret Dewsbury, chair of communities committee, said: 'I was surprised to hear that so many people across Norfolk are unaware they have high blood pressure. That equates to almost 100,000 people.'

There are around 50 pharmacies across the region offering to check people's blood pressure for free.

The condition, which has no obvious symptoms, can be managed through medication and changes in lifestyle. But the county council said in order for that to happen, the individual needs to know they have it.

Often, the first time someone realises they might have high blood pressure is after they have had a stroke or a heart attack.

Norfolk County Council's website features a map detailing all of the pharmacies offering blood pressure checks for free.

The council said the test is quick and simple with immediate results.

Louise Smith, director of public health said: 'The good news is that high blood pressure can be prevented and effectively treated.

'Keeping to a healthy weight, reducing the salt in your diet and drinking less alcohol can reduce your risk of high blood pressure.'

The council said the prevalence of high blood pressure is driven largely by the age of the population.

Other risk factors, such as excess weight, lack of exercise, high alcohol consumption, poor diet and ethnicity also contribute towards higher levels in the population. It estimates that North Norfolk has the highest undiagnosed rate, at almost one in five, while Norwich has the lowest at one in eight.

To check where your nearest participating pharmacy is visit www.norfolk.gov.uk/getchecked or to take part in the NHS Heart Age tool to find out how old your heart really is visit www.nhs.uk/conditions/nhs-health-check/check-your-heart-age-tool/

John's story

John Atkins, from Blofield, said he found out he had high blood pressure by accident.

He said: 'I led what I thought was a relatively healthy lifestyle, I enjoyed the odd glass of wine, but I was pretty active.

'When I found out I had high blood pressure I was pretty shocked.

'I found out by accident really, my brother is a GP and whilst waiting to meet him one day after work I was tempted to try out one of the 'test your own' blood pressure monitors in the surgery. '

He said the test revealed he had high blood pressure and he later prescribed medication to reduce it.

'It was only when I found out I had high blood pressure I realised it effected quite a few people I knew too, it is surprisingly common,' John said.

'The worrying thing is it really can have no symptoms so you may not know you even have it. That's why I was so keen to share my story, high blood pressure can be easily treated but only if you know you've got it.'

Ian's story

Ian Williams, 55, from Norwich, said he had to go to accident and emergency after having his pressure checked.

'I was on holiday in France and I developed a headache that I couldn't seem to shake off,' He said.

'On my return to Norfolk I went to the walk in centre and the first thing they did was to check my blood pressure.

'They were shocked at how high it was and I was eventually told to go to A&E four days later as my blood pressure was getting higher and higher.

'I was given medication to help bring my blood pressure down and the scare made me look at ways of changing my lifestyle to help improve my health.

'I would advise anyone to get their blood pressure checked and not to ignore nagging symptoms.

'I was lucky in a way as the headaches made me go to the doctor, but very often high blood pressure has no symptoms so unless you get yourself checked you may not know you have it.'