High blood pressure is the #2 cause of kidney failure. It accounts for about one-fourth of all cases. High blood pressure can be both a cause of kidney disease and a symptom of kidney disease. When high blood pressure damages your kidneys, they are not able to do all their jobs as well—and one of their jobs is helping your body regulate your blood pressure.
What is high blood pressure?
Your heart pumps your blood through your body using tubes called arteries and veins. When the blood moves through your arteries and veins, it makes pressure inside of the tubes. This is called blood pressure. Checking your blood pressure tells your doctor how hard your heart is working to pump your blood.
Blood pressure that is too high (hypertension) means your heart is working too hard to pump your blood. This can harm your body, including your kidneys. High blood pressure can cause kidney disease and kidney failure. Kidney disease can also cause high blood pressure.
How does high blood pressure cause kidney disease?
Your kidneys are made of tiny blood vessels, called glomeruli, which clean your blood. When you have high blood pressure, the blood flows through these blood vessels very forcefully. This can harm these blood vessels and cause kidney disease.
You will not be able to feel if high blood pressure has hurt your kidneys. The only way to know is to be tested. Learn more about the tests for kidney disease here.
How can I prevent kidney disease caused by high blood pressure?
It can take many years for high blood pressure to damage your kidneys. You can take steps to control your blood pressure and prevent kidney disease. If you already have kidney disease, controlling your blood pressure can help prevent more damage to your kidneys.
To prevent kidney disease or keep kidney damage from getting worse, you should:
- Control your blood pressure
- Follow a heart-healthy diet
- Control your blood sugar if you have diabetes
- Do not smoke or use tobacco
- Limit alcohol
- Keep a healthy weight
- Exercise most days of the week
Controlling your blood pressure
Your doctor may suggest that you check your blood pressure at home. The easiest way to do this is to use a digital blood pressure monitor. You can get a monitor from your local drug store, hospital, clinic or online. Your doctor can help you find a monitor that is right for you and show you how to use it. Many pharmacies and grocery stores also have in-store monitors that you can use for free.
The blood pressure monitor you choose will come with instructions on how to check your blood pressure. You should read these instructions and take your blood pressure monitor with you to your next doctor appointment. Ask your doctor to help make sure you are using the monitor correctly.
Understanding your results
When you check your blood pressure, your result will be given as two numbers. Both numbers are important.
- The first number (or top number) is your systolic pressure. This is the pressure in your arteries and veins when your heart is beating and the pressure is at its highest.
- The second number (or bottom number) is your diastolic pressure. This is the pressure in your arteries and veins when your heart is between beats and the pressure is at its lowest.
For most people a normal blood pressure is less than 120/80 (or 120 over 80). This means that your systolic pressure should be 120 or less and your diastolic pressure should be 80 or less. If either number is too high, your blood pressure is high.
Ask your doctor what your blood pressure should be and how often you should check it (or have it checked).
Follow a heart-healthy diet
What you eat and drink can affect your blood pressure. Choose foods that are low in salt (sodium) and fat to help keep your blood pressure in a healthy range. Use these tips to get started:
- Limit salt
- Do not add salt to your food when cooking or eating. Try cooking with fresh herbs, lemon juice or spices.
- Choose fresh or frozen vegetables instead of canned. If you do use canned vegetables, rinse them with water before eating or cooking them. This helps to remove extra salt.
- Shop for items that say “reduced-sodium” or “low-sodium.” If you have kidney disease, make sure to check that these items do not contain potassium as a salt-substitute.
- Avoid processed foods, such as frozen dinners and lunch meats.
- Limit fast food and salty snacks, such as chips, pretzels and salted nuts.
- Limit foods that are pickled or preserved, such as pickles and olives.
- Limit fat
- Choose lean meats or fish. Remove the skin and trim the fat off of your meats before you cook them.
- Bake, grill or broil your foods instead of frying them.
- Shop for fat-free or low-fat dairy products, salad dressing and mayonnaise.
- Try olive or canola oil instead of vegetable oil.
- Choose egg whites or egg substitute instead of whole eggs.
Talk to a dietitian about other ways to limit salt and fat in your diet. Your doctor can help you find a dietitian in your area. Medicare and private insurance policies may cover your appointment with a dietitian.
Having both diabetes and high blood pressure can increase your chances of getting kidney disease. If you have diabetes, work with your doctor to manage it.
Control your cholesterol
Cholesterol is a waxy, fat-like substance in your blood. Having high cholesterol and high blood pressure makes it more likely that you will have kidney disease, heart disease or a stroke. High cholesterol can also make kidney disease get worse faster.
There are two types of cholesterol you should pay attention to: HDL (“good” cholesterol) and LDL (“bad” cholesterol). For most people, normal cholesterol levels are:
- Total cholesterol: less than 200
- HDL (“good” cholesterol): more than 40
- LDL (“bad” cholesterol): less than 100
Your triglycerides are also important. Triglycerides are a type of fat in your blood. For most people, a healthy triglyceride level is less than 150.
Talk with your doctor about what your cholesterol and triglycerides levels should be and how you can control them.
Do not smoke or use tobacco
Using tobacco (smoking or chewing) 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 prevent your kidney disease from getting worse if you already have it.
Drinking alcohol in large amounts can make your blood pressure too high. Limiting how much alcohol you drink can help keep your blood pressure under control. Have no more than two drinks per day if you are a man and no more than one drink per day if you are a woman.
Keep a healthy weight
Keeping a healthy weight can help you control your blood pressure and lower your chances of getting kidney disease. Talk to your doctor about how much you should weigh. If you are overweight, losing just a few pounds can make a big difference.
Exercise most days of the week
Exercise can help you control your blood pressure and cholesterol. Exercise can also help relieve stress, another common cause of high blood pressure.
To get the most benefit, exercise for at least 30 minutes, five days a week. If that seems like too much, start slowly and work your way up. Look for fun activities that you enjoy. Try walking with a friend, dancing, swimming or playing a sport. Adding just a little more activity to your routine can help.
Be sure to talk to your doctor before starting any exercise program.
How is high blood pressure treated?
If changes to your lifestyle are not enough to control your blood pressure, your doctor may tell you to take a blood pressure medicine. There are many types of blood pressure medicine and you may need to take more than one to control your blood pressure.
ACE inhibitors and ARBs are two types of blood pressure medicines that can help protect your kidneys.
- ACE inhibitor: angiotensin-converting enzyme inhibitor
- ARB: angiotensin II receptor blocker
Ask your doctor if one of these is right for you. Your doctor might also ask you to take a diuretic (also called a water pill). This is a type of medicine that helps your body get rid of extra fluid. Having extra fluid in your body can make your blood pressure too high.
If your doctor tells you to take any medicine, take your medicine the way your doctor tells you to. Blood pressure medicine works best when you take it every day, even if you feel fine. If you have any side effects from your medicine, talk to your doctor. You may be able to take a different medicine that does not have those side effects.
If you have trouble remembering to take your medicine, try to:
- Set an alarm to remind yourself.
- Use a pill box to keep your medicines organized.
- Take your medicine at the same time every day as part of your normal routine, such as when you brush your teeth or eat a meal.