Having high blood pressure can cause a number of serious diseases including heart attacks and strokes.
Also known as hypertension, it's estimated to affect over a quarter of adults in the UK, equating to around 14.4 million people.
Blood pressure readings are given in two numbers with the top number being the maximum pressure the heart exerts while beating (systolic pressure). The bottom number is the amount of pressure in the arteries between beats (diastolic pressure).