New pills to treat high blood pressure could soon be available after a medical breakthrough by scientists.
The discovery could lead to better regulation of blood pressure - a condition that affects a third of adults.
Currently many patients take a combination of blood pressure pills that relax and widen blood vessels, flush excess water and salt from the body or make the heart beat more slowly and with less force.
If blood pressure is too high, it puts extra strain on blood vessels, heart and other organs, such as the brain, kidneys and eyes.
Untreated it can lead to potentially deadly conditions such as heart disease, heart attacks, strokes, heart failure, peripheral arterial disease, aortic aneurysms, kidney disease and vascular dementia.
Researchers at King's College London discovered nitric oxide that regulates blood pressure is formed in nerves rather than in the walls of blood vessels.
The surprise findings follows a world-first study in healthy humans given a drug that prevented an enzyme in the nerves from producing nitric oxide.
Once the enzyme had stopped producing nitric oxide the team were able to measure the impact the gas from that source has.
To their surprise, reducing production of nitric oxide led to a significant increase in the force that opposes the flow of blood, known as vascular resistance, and blood pressure itself.
Professor Ajay Shah, BHF Chair of Cardiology at King's College Hospital said: "We used an inhibitor drug to stop an enzyme in the nerves from producing nitric oxide.
"While we suspected that stopping this enzyme would have some effect, we were surprised at how much influence it has on blood pressure.
"Our discovery will fundamentally change the way we view the regulation of blood pressure.
"Until now the majority of blood pressure drugs have focused on other pathways.
"Establishing that nerves releasing nitric oxide influence blood pressure, provides a new target for drugs and could eventually lead to more effective treatments for patients."
Professor Jeremy Pearson, Associate Medical Director at the British Heart Foundation which part funded the research said: "The British Heart Foundation estimates that nearly 30 per cent of adults in the UK are living with high blood pressure, putting them at risk of having a heart attack or stroke.
"Understanding how blood pressure is regulated is crucial if we hope to develop new potential treatments to lower it.
"This study adds a very unexpected piece to the puzzle of blood pressure regulation.
"Whilst there are already many treatments for high blood pressure, they are not always effective.
"These results provide hope of new treatments for people with poorly controlled high blood pressure, which could prove crucial in preventing a heart attack or stroke."
The study published in the journal Hypertension builds on previous work that established the fundamental role that the gas nitric oxide plays in regulating blood pressure.
It only came to prominence around 25 years ago when a group of American pharmacologists discovered its properties as a 'signalling system' in the cardiovascular system which earned them the Nobel Prize for Medicine in 1998.
Further research proved the crucial role the gas plays in such fundamental biological processes such as regulation of blood pressure, functioning of the immune system, and different functions of the nervous system.
Importantly, it works as a vasodilator, relaxing narrowed blood vessels, increasing blood flow and oxygen delivery to vital organs.
The anti-impotence drug Viagra was created through this research.
Professor Phil Chowienczyk, Professor of Clinical Pharmacology at King's said: "This link between release of nitric oxide from nerves and blood pressure is fascinating because it provides new insight into how blood pressure is controlled by the brain and into how mental health might affect blood pressure."