Oxford study: One in eight people might have blood pressure without knowing


Why You Might Have High Blood Pressure And Not Even Know It! One in eight adults have nighttime spikes missed due to daytime GP appointments, study suggests

  • Fifteen percent of adults aged 40 to 75 had high blood pressure in the evening
  • Oxford University experts say they would be missed during the day
  • Hypertension increases the risk of heart attacks, strokes and even death







Millions of Britons may be suffering from high blood pressure unknowingly because their levels only peak at night, research suggests.

A study from the University of Oxford found that one in eight people aged 40 to 75 had evening hypertension that would be missed by a daytime GP appointment.

Having high blood pressure increases your risk of heart attacks, strokes, and even death — especially if left untreated.

Healthy people usually see their blood pressure drop at night as the body relaxes and prepares for sleep.

But researchers found that the opposite happens in 15 percent of people.

The NHS watchdog NICE currently recommends that GPs diagnose patients based on daytime blood pressure alone.

But the Oxford team and ambulatory monitoring — when a cuff is worn over a 24-hour period — should be used more often.

Millions of Britons may be suffering from high blood pressure unknowingly as their levels only peak at night (file image)

Millions of Britons may be suffering from high blood pressure unknowingly as their levels only peak at night (file image)

Lead study author Professor Lionel Tarassenko said: ‘Daytime blood pressure measurements are not enough.

‘Blood pressure follows a cyclical pattern over 24 hours. Normally, it drops at night during sleep and then rises after waking.

‘With ‘reverse dippers’ – usually the elderly, sometimes with diabetes or kidney disease – the pattern is reversed. Blood pressure goes up at night and then drops after waking.

‘That means that ‘reverse dippers’ have the lowest blood pressure during the day and are therefore falsely reassured by daytime monitoring at home or in the general practice.’

The study involved approximately 21,000 patients from 28 GP practices and four hospitals in the Oxford area.

In hospitalized patients, researchers found that nearly half (49 percent) of these patients were “reverse-dippers.”

About 15 percent of the community participants had high blood pressure at night.

In both hospital and community patient groups, one in three reverse dippers had at least one cardiovascular disease.

GP Laura Armitage, a researcher in the Nuffield Department of Primary Care Health Sciences at the University of Oxford, added: ‘Our research shows that measuring nighttime blood pressure can help identify one in eight adults in England with undiagnosed hypertension.

‘It is important that this also leads to a reduction in cardiovascular diseases and mortality.

“This highlights the need for GPs to offer 24-hour blood pressure monitoring to their patients.”

The research is published in the British Journal of General Practice.


High blood pressure or hypertension rarely has noticeable symptoms. But if left untreated, it increases your risk of serious problems such as heart attacks and strokes.

More than one in four adults in the UK has high blood pressure, although many don’t realize it.

The only way to find out if your blood pressure is high is to have your blood pressure checked.

Blood pressure is recorded with two numbers. The systolic pressure (higher number) is the force with which your heart pumps blood around your body.

The diastolic pressure (lower number) is the resistance to blood flow in the arteries. They are both measured in millimeters of mercury (mmHg).

As a general guide:

  • high blood pressure is considered 140/90 mmHg or higher
  • ideal blood pressure is considered to be between 90/60 mmHg and 120/80 mmHg
  • low blood pressure is considered to be 90/60 mmHg or lower
  • A blood pressure reading between 120/80 mmHg and 140/90 mmHg can mean you are at risk of developing high blood pressure if you don’t take steps to control your blood pressure.

If your blood pressure is too high, it puts extra strain on your blood vessels, heart and other organs, such as the brain, kidneys and eyes.

Persistent high blood pressure can increase your risk for a number of serious and potentially life-threatening conditions, such as:

  • heart disease
  • heart attacks
  • to succeed
  • heart failure
  • peripheral arterial disease
  • aortic aneurysms
  • kidney disease
  • vascular dementia

Source: NHS