High Blood Pressure and Kidney Disease
Blood pressure measures the force of your blood on the walls of your arteries in two ways:
- Right after your heart beats (systolic blood pressure)
- In between heartbeats (diastolic blood pressure)
That is why blood pressure readings are given as two numbers. For example, with a blood pressure of 130/85 mm Hg, the systolic pressure is 130 and the diastolic pressure is 85. It is important to make sure that both your diastolic and systolic blood pressure goals are being achieved.
High blood pressure is also called hypertension. It is defined as blood pressure readings greater than 140/90 mm Hg*. In people with diabetes, blood pressure should be less than 130/80. For some people with kidney disease, even lower blood pressures are ideal.
One out of every five Canadian adults has high blood pressure. The incidence of this disease increases with age. It is important for people with high blood pressure to know their blood pressure goals, and to try to make sure that their blood pressure is lowered until is below the target level.
*Blood pressure goals vary depending on the individual. Discuss your blood pressure goal with your doctor.
High blood pressure risk factors
The causes of high blood pressure are not fully understood. The risk factors that can lead to high blood pressure include:
- Family history of high blood pressure
- Being overweight
- Age — People over 50 years old are at greater risk for high blood pressure, but high blood pressure can occur at any age.
- Race — African-Americans have a higher incidence of high blood pressure and a greater chance of developing kidney damage from high blood pressure; however, high blood pressure is common in all races.
- Too much salt in the diet
- Cigarette smoking
- Too much alcohol (more than two standard drinks per day)
- Lack of physical activity
How to know if you have high blood pressure
High blood pressure is a silent disease. There are no clear signs or warning signals. Usually, the only way you can tell if your blood pressure is high is to have it checked by a healthcare professional. Blood pressure readings can vary quite a lot so a single abnormal or high reading does not always mean you have high blood pressure. If your first reading is higher than your blood pressure goal, you should have it checked on two more occasions to confirm that you have high blood pressure. Of course, if your blood pressure is very high, your doctor may start treatment right away.
You should have your blood pressure measured at least once a year.
Blood Pressure Being Taken
High blood pressure and kidney disease
Kidney disease can lead to high blood pressure in many people. The opposite is also true: having high blood pressure increases the risk of developing kidney disease. High blood pressure can damage the kidneys. This reduces the kidneys' ability to remove fluids and waste products from the blood, and can lead to kidney failure. When the kidneys fail, their function needs to be replaced, either through dialysis treatments or a kidney transplant.
Controlling high blood pressure is important
Proper control of high blood pressure can prevent many of its complications. If high blood pressure is not well-controlled, it can increase the chance of stroke, heart attack, heart failure, kidney failure and damage to the blood vessels of the legs leading to amputation.
If you have diabetes as well as high blood pressure, you must be especially careful about good blood pressure control. For people with kidney disease, good blood pressure control can slow down the decrease in kidney function.
At present there is no cure for high blood pressure. However, it can be treated and controlled to reduce the chances of developing problems. If you have high blood pressure or wish to prevent it, you may have to make some changes in your lifestyle including:
- Eating healthy foods (low in fat and salt)
- Quitting smoking
- Keeping a healthy body weight
- Getting regular exercise
- Cutting down on alcohol
- Learning to relax and taking time to do the things you enjoy
You will need to take medication if your blood pressure is very high or if lifestyle changes do not lower your blood pressure to normal. In most cases, you will need to take medication for the rest of your life. There are many types of blood pressure medication and, since everyone's needs are different, your doctor will decide which medication is best for you.
Controlling high blood pressure takes a team effort and you are the most important person on the team. Be sure to see your doctor regularly. Do not stop taking your blood pressure medication without talking to your doctor. It is important to remember that good control of high blood pressure can reduce the chance of future health problems. A healthy lifestyle and the right medications can help you reach your goal of good blood pressure control.
With acknowledgement to Dr. Philip A. McFarlane, FRCPC, nephrologist, at St. Michael's Hospital in Toronto, Ontario, for his assistance in reviewing this information.