Treating tiny benign tumours in the adrenal glands may prevent huge numbers of cases of high blood pressure, say researchers.
The team at the University of Cambridge and Addenbrooke's Hospital think that up to 10 percent of cases may be caused by the growths.
Their study, published in Nature Genetics, said young patients could be freed from a lifetime of medication. The British Heart Foundation said it was an "exciting development".
High blood pressure can have fatal consequences as it increases the risk of heart attacks and stroke.
Most cases are caused by lifestyle choices such as smoking and diet.
Researchers had already found that large growths in the adrenal glands, which sit on the kidneys and produce hormones, could raise blood pressure. An operation to remove any tumours can reduce blood pressure.
Now the researchers in Cambridge have found that much smaller growths, in a different part of the glands, are producing the same effect.