You probably have high blood pressure (hypertension) if your blood pressure readings are consistently 140 over 90, or higher, over a number of weeks.
You may also have high blood pressure if just one of the numbers is higher than it should be over a number of weeks.
If you have high blood pressure, this higher pressure puts extra strain on your heart and blood vessels. Over time, this extra strain increases your risk of a heart attack or stroke.
High blood pressure can also cause heart and kidney disease, and is closely linked to some forms of dementia.
You can check your blood pressure on our Blood Pressure Chart.