Blood pressure is the force exerted by blood on the walls of the arteries, depending on whether the heart muscle is contracting (systolic blood pressure), or relaxing between contractions (diastolic blood pressure). High blood pressure, also known as raised blood pressure or hypertension, is where blood pressure is permanently higher than normal.
Untreated high blood pressure is a key risk factor for the development and progression of chronic kidney disease (CKD). It can damage the blood vessels in the kidneys, leading to reduced blood supply and making waste and fluid removal difficult (Webster et al. 2017). Extra fluid can, in turn, raise blood pressure and cause more damage, ultimately leading to kidney failure.
High blood pressure is also a risk factor for cardiovascular events in people with CKD or kidney failure. Drug treatment and changes to health-related behaviours (such as weight loss, a healthy diet and physical activity) can help to control blood pressure.
In the ABS National Health Survey 2017–18, people aged 18 years and over could consent to having a blood pressure measurement taken at the time of the interview. ‘Uncontrolled high blood pressure’ is reported for participants with a systolic blood pressure reading 140 mmHg or more, or diastolic blood pressure of 90 mmHg or more, or receiving medication for high blood pressure (ABS 2018).
Blood pressure is considered to be uncontrolled if measured levels of systolic or diastolic blood pressure are high, regardless of the use of blood pressure medication. ‘Controlled blood pressure’ refers to those people who are taking blood pressure medication and have a normal blood pressure reading.