High blood pressure and kidney health

What is high blood pressure? 

Blood pressure is the force of blood pumping through 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, also called end-stage renal disease (ESRD) or end-stage kidney disease. It can also lead to other health problems including heart attack or stroke.

To find out if you have high blood pressure, your doctor will measure your blood pressure with a blood pressure cuff. Blood pressure measurements include two numbers, which 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 or normal blood pressure for adults is less than 120/80 (120 over 80). For most healthy adults, a blood pressure of 130/80 or more is too high. Only a doctor or medical professional can confirm high blood pressure and can also check if your blood pressure is too low.

One high blood pressure reading may not necessarily mean you have high blood pressure. Your blood pressure can change throughout the day depending on your activities and what you eat or drink. Sometimes, your blood pressure can be higher than usual at a doctor's office if you are nervous or stressed. High blood pressure is a pattern, usually diagnosed after several readings over time. Your doctor will confirm if you have high blood pressure and will want to monitor it in future visits. Ask your doctor what your blood pressure should be and how often you should check it. Your doctor can also teach you how to check your blood pressure at home so you can watch it more closely. 

Why is early detection important?

High blood pressure often does not cause any noticeable symptoms, so many people don't know they have it.  

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.

Checking your blood pressure regularly can help:

• 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.
• Protect your kidneys from long-term 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's often irreversible.

High blood pressure can be part of a larger group of health problems known as cardiovascular kidney metabolic syndrome (CKM).  Experts have found that people with heart disease (also called cardiovascular disease) have a higher chance of other health conditions, such as kidney disease, type 2 diabetes and obesity. Likewise, people with kidney disease, type 2 diabetes or obesity also have a higher chance of getting heart disease. Understanding your risk for CKM and managing these related conditions can help protect your heart and kidneys.

High blood pressure can affect anyone, but some communities face greater challenges in detecting and managing it. Studies show that Black and Hispanic individuals are more likely to have high blood pressure and more likely to develop kidney failure. By detecting high blood pressure early, you can take steps to manage it, protect your health, reduce risks, and prevent complications before they start. 

How will I know if my high blood pressure is harming my kidneys?

To know if your kidneys have been damaged, your doctor may do tests, including: 

• A blood test to check your estimated glomerular filtration rate (eGFR), which shows how well your kidneys are working
• A urine albumin-to-creatinine ratio (uACR) test to check for protein (albumin) in your urine (pee)
• Imaging tests: To look at your kidneys, such as an ultrasound, CT scan, X-ray or MRI

Can kidney damage from high blood pressure be reversed?

In the early stages of kidney disease, managing your blood pressure with medicines, lifestyle changes, and regular monitoring can slow down or even stop further damage. In some cases, kidney function may improve slightly with treatment, but most damage from high blood pressure is permanent. That's why early detection and consistent blood pressure control are so important. Talk to your doctor about your kidney numbers and what steps you can take to protect them now.

How is high blood pressure treated?

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

• Follow a low-sodium (salt) eating plan as salty foods can make your body hold onto fluids which can raise 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. 

Your doctor may also prescribe you medicines to help control your blood pressure. These can include: 

• Angiotensin converting enzyme inhibitors (ACE inhibitors) and angiotensin receptor blockers (ARBs) help relax your blood vessels and lower your blood pressure. If you have side effects on one, switching to the other can help.  
• Beta blockers make it easier for the heart to pump blood and can be used to slow the heart rate.
• Calcium channel blockers which can relax your blood vessels and lower the workload on your heart.  
• Diuretics ("water pills") lower your blood pressure by removing extra fluid from your body, which helps your kidneys get rid of salt and water.  
• Vasodilators widen your blood vessels for blood to flow easily.

Work with your healthcare team, which may include a Nephrologist (kidney specialist), a Cardiologist (heart specialist), and a registered dietitian to understand treating and managing your conditions.

Be sure to take your blood pressure medicines the way your doctor tells you to, even if you feel fine.

If you take blood pressure medicine every day, your doctor may want you to check your blood pressure at the same time each day before taking your medicine. This helps your doctor see how well your medicine is working to control your blood pressure. Talk to your doctor if you have any side effects from your medicines. They may be able to change your dose or switch to a different medicine.

What is resistant hypertension?

Resistant hypertension (RH) is when your blood pressure stays 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 may refer you to a specialist, such as a heart doctor (cardiologist) or a kidney doctor (nephrologist). Since people with RH are at risk for other serious health problems, like stroke or heart attack, it's important to take your medicine exactly the way your doctor tells you.

What is renal hypertension?

Renal hypertension or renovascular hypertension, is high blood pressure caused by a problem with the kidneys. It happens when the arteries that carry blood to the kidneys become narrow, reducing blood flow. In response, the kidneys trigger a hormone system that raises blood pressure throughout the body, and your kidneys receive less blood than they should. This type of high blood pressure often doesn't cause symptoms but can be hard to control with medicines alone. It's more likely to show up early in life or later in adulthood and can lead to kidney disease or heart complications if untreated. Renal hypertension is often a cause of resistant hypertension.

Renal hypertension often doesn't show symptoms until blood pressure becomes dangerously high.

When symptoms appear, they may include:

• Headaches
• Vision changes
• Shortness of breath
• Confusion
• Chest pain

If your blood pressure is 180/120 or higher and you have these symptoms, you may be having a hypertensive crisis which is an emergency. Wait 1 — 2 minutes and check your blood pressure again. If it's still very high and you have symptoms, call your doctor right away. Call 911 if you are experiencing chest pain, shortness of breath, back pain, numbness, weakness, change in vision or changes in speaking. Your doctor may need to change your blood pressure medicine to help keep you safe.

How can I prevent kidney disease caused by high blood pressure?

High blood pressure can slowly damage your kidneys over time. If you already have kidney disease, it's important to control your blood pressure. Controlling your blood pressure can help avoid more damage to your kidneys and prevent heart 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 kidney-friendly eating plan. What you eat and drink can change your blood pressure. Choose foods that are low in salt and fat to help keep your blood pressure in a healthy range. You can ask your healthcare provider for a referral to a registered dietitian.
• Be active. Try to get at least 30 minutes of physical activity most days of the week. Walking, cycling, or dancing are good choices. Be sure to talk to your doctor before starting any exercise plan.
• Take all your prescription medicines as your doctor tells you. Track your blood pressure readings and medications.
• Manage your diabetes. If you have diabetes, work with your doctor to manage it by keeping your blood sugar in a healthy range. Having both diabetes and high blood pressure can make you more likely to get kidney disease.
• 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 cause or worsen kidney disease. Talk with your doctor about what your cholesterol levels should be and how you can keep it in a healthy range.
• Limit how much alcohol you drink. If you choose to drink alcohol, experts recommend no more than two drinks a day for men and one drink a day for women.
• 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.

Learn more about kidney disease and prevention