What is high blood pressure?
The circulatory system needs the right amount of pressure to move blood around your body. When you have high blood pressure, also known as hypertension, your blood pressure is consistently higher than the recommended level. It’s not something you’ll usually notice in day-to-day life, but if it’s not diagnosed or treated, your heart may become enlarged over time due to the increased pressure. An enlarged heart pumps less effectively, and sometimes leads to heart failure. High blood pressure increases the risk of having a heart attack or stroke.
Find out more about the symptoms and causes of high blood pressure.
A sunny way to treat high blood pressure
When you think about preventing or reversing high blood pressure, you might think of reducing salt intake, losing weight and increasing the amount of exercise you do. But BHF-funded researchers are looking at other ways to make a difference. They’re exploring whether exposure to sunlight can help to reduce blood pressure.
Dr Richard Weller and his team at the University of Edinburgh have discovered that giving a single dose of artificial ultraviolet (UV) light to healthy people can reduce their blood pressure. The team thinks this could be because UV light mobilises a molecule called nitric oxide from the skin, which relaxes blood vessels and lowers blood pressure.
To see if UV light exposure is truly a drug-free way to help treat high blood pressure, Dr Weller’s team are carrying out a clinical trial. They will give people with mild high blood pressure a dose of UV light twice a day to see if this lowers their blood pressure to a sustained healthy level.
An app to reduce your blood pressure
Professor Susan Jebb from the University of Oxford wants to help people reduce their salt intake, to reduce their risk of high blood pressure. To do this, she and her team are conducting interviews to understand the reasons behind people’s food choices. She will use this information to produce a smartphone app to help find replacements for food high in salt.
In the future, healthcare professionals could refer people who are newly diagnosed with high blood pressure to this app, to help them understand how much salt is in the foods they usually eat, so they’re able to switch to foods with less salt. The app would be a low-cost way to change behaviour and reduce hypertension.
Blood pressure and the ‘selfish’ brain
We know that high blood pressure can be lowered with lifestyle changes and medication, but in severe cases, these treatments aren’t enough to combat it. Professor Julian Paton at the University of Bristol is interested in the link between blood pressure and the brain. The brain is connected to the heart and blood vessels by nerves, which help to control blood pressure. Professor Paton believes that reduced blood flow through small vessels of the brain can cause high blood pressure. The theory is that the brain senses that its blood flow is low and fires off signals through the nerves. This increased nerve activity raises whole body blood pressure to push more oxygen-rich blood through the brain. In this way, the brain preserves its own blood supply, but at the expense of causing hypertension (the selfish brain hypothesis).
Although the selfish brain hypothesis was suggested some time ago, until now, scientists haven’t been able to perform the complicated experiments needed to prove it. In a programme of work funded by the BHF, Professor Paton has been using cutting edge approaches to study how exactly the brain controls blood pressure, in the hope that this will lead to new treatments for high blood pressure that doesn’t respond to medication
The difference we’ve already made
In the early 1950s high blood pressure was treated with medication that had very undesirable side effects – for example, patients were prone to fainting.
Beta blockers were developed in the 1960s and over the next two decades angiotensin-converting enzyme (ACE) inhibitors became standard treatment for people with high blood pressure.
Since then, our research has shown the benefits of treating high blood pressure in very elderly people, helping to change treatment guidelines for this group of people. And BHF funded studies have revealed a cheap and effective add-on therapy for resistant high blood pressure, as well as insights into the underlying causes of high blood pressure, progressing the search for new treatment targets.
Find out more about our successes in high blood pressure research.