High blood pressure and kidney health

What is high blood pressure? 

Blood pressure is the force of blood pumping through your blood vessels (the tubes that carry blood to your organs). If this force is too high, your heart is working too hard to pump 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?

Your kidneys filter all the blood in your body about 40 times a day to remove waste and toxins. Over time, high blood pressure damages the blood vessels that deliver blood to your kidneys, causing them to retain more salt, water, and toxins. This can further increase your blood pressure, creating a cycle that may eventually lead to kidney failure.

Why is early detection important?

High blood pressure is known as a silent killer because it usually doesn't show symptoms until it's dangerously high. By the time symptoms like headaches, vision problems, or confusion occur, significant damage may have already been done to your heart, blood vessels, and kidneys.

Keeping an eye on your blood pressure can:

• Prevent other health issues: Regular blood pressure checks can catch hypertension early, allowing for treatment before it leads to serious complications like kidney disease, heart disease, or stroke.
• Avoid irreversible damage: High blood pressure can quietly damage your kidneys over time by straining the blood vessels they rely on to filter waste. Once kidney damage becomes advanced, it is often irreversible.

High blood pressure affects everyone, but some communities face greater challenges in detecting and managing it. Studies show that Black and Hispanic individuals often receive a diagnosis of high blood pressure or related conditions, like kidney disease, later than others. By detecting high blood pressure early, you can take steps to protect your health, reduce risks, and prevent complications before they start. 

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 is high blood pressure treated?

Lifestyle changes can help lower blood pressure and protect your kidney health:

• Follow a low-sodium (salt) eating plan to prevent fluid retention and high blood pressure.
• Be active for at least 30 minutes most days of the week to improve heart health and control your weight.
• Quit smoking or using tobacco, as this can make high blood pressure worse and damage blood vessels.
• Drink less alcohol, which can also contribute to high blood pressure. 

If healthy life changes aren't enough to control your blood pressure, your doctor may prescribe blood pressure medicine. These can include: 

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. 

It is important to measure your blood pressure before you take your medicine and track it to inform your doctor of how well your blood pressure is controlled. 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.

What is resistant hypertension?

Resistant hypertension (RH) is when your blood pressure is higher than your target goal, even though you're taking three types of blood pressure medicine, including a water pill, at the highest doses. People who need four or more medicines to control their blood pressure also have RH. If you have RH, your doctor will refer you to a hypertension specialist, such as a kidney doctor (nephrologist). Since people with RH are at risk for other serious health problems, including stroke, heart attack, and even death, it's important to take your medicine as prescribed.

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 avoid more damage to your kidneys and prevent cardiovascular disease. 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 cause kidney disease worsen 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.