A study concluded it could lead to a 65 per cent cut in strokes and 45 per cent in coronary heart disease, according to the journal Hypertension.
The figures suggest more than a third of patients with high blood pressure do not take their medication, often because they forget.
But more than 50 per cent who took a urine test became “completely adherent” to taking their prescription, while 30 per cent improved in sticking to their regime.
Of 238 people tested, 73 were not taking their blood pressure tablets regularly.
Blood pressure changes for the 73 were tracked after an appointment at which the urine test was discussed.
Their blood pressure usually fell between the test and final clinic visit.
Professor Maciej Tomaszewski led a team from the Universities of Manchester, Leicester and University College London.
He said: “The urine test creates an opportunity for patients and their doctors to discuss the barriers to regular taking of blood pressure medications.
“The doctors can then act on these barriers and provide the support the patients need to adhere to the treatment regimes.”