High blood pressure
- Medically reviewed by
- AKF's Medical Advisory Committee
- Last updated
- October 28, 2021
What is high blood pressure?
Blood pressure is the force of your blood pumping through your blood vessels (the tubes in your body that carry blood to your organs). If this force is too high it means your heart is working too hard to pump your blood. In time, high blood pressure can damage your blood vessels, which can lead to serious health problems including kidney failure.
How does high blood pressure affect my kidneys?
Here is how high blood pressure can affect your kidneys:
- Your kidneys need a lot of blood in order to filter fluid and waste out of your body.
- If high blood pressure damages the blood vessels that deliver blood to your kidneys, your kidneys will act as if you are dehydrated (do not have enough water in your body).
- So, your kidneys will tell your body to hold on to extra salt and fluid.
- As your blood fills with this extra salt and fluid, your blood pressure goes up. In time, this can lead to kidney failure.
What are the symptoms of high blood pressure and kidney disease?
High blood pressure usually does not cause symptoms, but dangerously high blood pressure can cause:
- Blurry or double vision
- Blood in your urine (hematuria)
Early kidney disease also may not have symptoms. As kidney disease gets worse, some people notice swelling in their legs, feet and ankles.
How will I know if I have high blood pressure?
To find out if you have high blood pressure, your doctor will measure your blood pressure with a blood pressure cuff. This will give your doctor two numbers. When you see these two numbers they will be separated by a slash:
- The first (top) number is your systolic pressure. This is the pressure in your blood vessels as your heart beats and pushes blood through your body.
- The second (bottom) number is your diastolic pressure. This is the pressure in your blood vessels between heartbeats.
A healthy blood pressure for adults is less than 120/80 (120 over 80). For most healthy people, a blood pressure of 140/90 or more is too high. If you have diabetes or kidney disease, a blood pressure of 130/80 or more is too high.
It takes more than one test for doctors to know if you have high blood pressure. Ask your doctor what your blood pressure should be and how often you should have it checked. Your doctor may also teach you to check your blood pressure at home so you can watch it more closely.
How will I know if my high blood pressure is affecting my kidneys?
To know if your kidneys have been damaged, your doctor may do tests, including:
- Blood tests: To help find out how well your kidneys still work
- Urine (pee) tests: To check for blood and protein in your urine or other signs of problems
- Imaging tests: To look at your kidneys, such as an ultrasound, CT scan, X-ray or MRI
How do doctors treat high blood pressure?
First, your doctor may suggest some healthy life changes. This may include:
- Following a low-sodium (salt) eating plan
- Being active for at least 30 minutes most days of the week
- Quitting smoking or using tobacco
- Drinking less alcohol
If healthy life changes are not enough to control your blood pressure, your doctor may give you a prescription blood pressure medicine. There are two types of blood pressure medicines that can also help protect your kidneys and slow down kidney disease:
- ACE inhibitors (Angiotensin-converting enzyme inhibitors): A group of medicines that lower blood pressure by widening your blood vessels, helping your kidneys get rid of extra water and lowering the levels of hormones that raise blood pressure
- ARBs (Angiotensin receptor blockers):A group of medicines that lower blood pressure by widening your blood vessels
Your doctor might also ask you to take a diuretic, also called a water pill. This helps your body get rid of extra fluid which can cause high blood pressure.
Be sure to take all medicines the way your doctor tells you to. Blood pressure medicines work best when you take them every day even if you feel fine.
Talk to your doctor if you have any side effects from your medicines. You may be able to take a different medicine that does not have those side effects.
Can damage to my kidneys from high blood pressure be reversed?
If kidney disease is caught early, it can often be reversed by treating the cause, such as high blood pressure. Once kidney disease reaches a more advanced stage, the damage cannot be reversed.
If you already have kidney disease, you may be able to slow down the damage to your kidneys by controlling your blood pressure.
How can I prevent kidney disease caused by high blood pressure?
It can take years for high blood pressure to damage your kidneys. If you already have kidney disease it is important to control your blood pressure. Controlling your blood pressure can help prevent more damage to your kidneys. Here are some steps you can take to control your blood pressure and prevent kidney disease:
- Keep a healthy weight. A healthy weight can help you control your blood pressure and lower your chances of getting kidney disease.Talk to your doctor about what a healthy weight is for you.
- Follow a healthy eating plan. What you eat and drink can change your blood pressure. Choose foods that are low in sodium (salt) and fat to help keep your blood pressure in a healthy range.
- Be active for 30 minutes most days of the week. Be sure to talk to your doctor before starting any exercise plan.
- Take all of your prescription medicines as your doctor tells you.
- Work with your doctor to control your diabetes.Having both diabetes and high blood pressure can make you more likely to get kidney disease. If you have diabetes, work with your doctor to manage it.
- Work with your doctor to manage your cholesterol. Cholesterol is a waxy, fat-like substance in your blood. Having both high cholesterol and high blood pressure can make you more likely to get kidney disease. High cholesterol can also make kidney disease get worse faster. Talk with your doctor about what your cholesterol level should be and how you can control it.
- Limit how much alcohol you drink. The healthy guidelines for drinking alcohol are:
- For men: No more than two drinks per day
- For women: No more than one drink per day
- Quit smoking or using tobacco. Tobacco can make high blood pressure and kidney problems worse. If you use tobacco, quitting can help lower your chance of getting kidney disease or help keep your kidney disease from getting worse.