Important Information on your health and kidney disease

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 The kidneys are two bean-shaped organs. Each kidney is about the size of a fist. Your kidneys filter extra water and wastes out of your blood and make urine. Kidney disease means your kidneys are damaged and can’t filter blood the way they should.

You are at greater risk for kidney disease if you have diabetes or high blood pressure. If you experience kidney failure, treatments include kidney transplant or dialysis. Other kidney problems include acute kidney injury, kidney cysts, kidney stones, and kidney infections.

The kidneys are two bean-shaped organs, each about the size of a fist. They are located just below the rib cage, one on each side of your spine.

Healthy kidneys filter about a half cup of blood every minute, removing wastes and extra water to make urine. The urine flows from the kidneys to the bladder through two thin tubes of muscle called ureters, one on each side of your bladder. Your bladder stores urine. Your kidneys, ureters, and bladder are part of your urinary tract.

 Your kidneys remove wastes and extra fluid from your body. Your kidneys also remove acid that is produced by the cells of your body and maintain a healthy balance of water, salts, and minerals—such as sodium, calcium, phosphorus, and potassium—in your blood.

Without this balance, nerves, muscles, and other tissues in your body may not work normally.

Your kidneys also make hormones that help

• control your blood pressure
• make red blood cells NIH external link
• keep your bones strong and healthy

Each of your kidneys is made up of about a million filtering units called nephrons. Each nephron includes a filter, called the glomerulus, and a tubule. The nephrons work through a two-step process: the glomerulus filters your blood, and the tubule returns needed substances to your blood and removes wastes. 

As blood flows into each nephron, it enters a cluster of tiny blood vessels—the glomerulus. The thin walls of the glomerulus allow smaller molecules, wastes, and fluid—mostly water—to pass into the tubule. Larger molecules, such as proteins and blood cells, stay in the blood vessel.

A blood vessel runs alongside the tubule. As the filtered fluid moves along the tubule, the blood vessel reabsorbs almost all of the water, along with minerals and nutrients your body needs. The tubule helps remove excess acid from the blood. The remaining fluid and wastes in the tubule become urine.

 Blood flows into your kidney through the renal artery. This large blood vessel branches into smaller and smaller blood vessels until the blood reaches the nephrons. In the nephron, your blood is filtered by the tiny blood vessels of the glomeruli and then flows out of your kidney through the renal vein.

Your blood circulates through your kidneys many times a day. In a single day, your kidneys filter about 150 quarts of blood. Most of the water and other substances that filter through your glomeruli are returned to your blood by the tubules. Only 1 to 2 quarts become urine. Children produce less urine than adults, and the amount produced depends on their age.

The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) and other components of the National Institutes of Health (NIH) conduct and support research into many diseases and conditions.

Clinical trials are part of clinical research and at the heart of all medical advances. Clinical trials look at new ways to prevent, detect, or treat disease. Researchers also use clinical trials to look at other aspects of care, such as improving the quality of life for people with chronic illnesses. Find out if clinical trials are right for you NIH external link.

 Chronic kidney disease (CKD) means your kidneys are damaged and can’t filter blood the way they should. The main risk factors for developing kidney disease are diabetes, high blood pressure, heart disease, and a family history of kidney failure. 

 If you have chronic kidney disease (CKD), you can take steps to protect your kidneys from more damage.

The sooner you know you have kidney disease, the better. The steps you take to protect your kidneys from damage also may help prevent heart disease—and improve your health overall. Making these changes when you have no symptoms may be hard, but it’s worthwhile.

You are more likely to develop kidney disease if you have

• diabetes
• high blood pressure
• heart disease
• a family history of kidney failure

Diabetes and high blood pressure are the most common causes of chronic kidney disease (CKD). Your health care provider will look at your health history and may do tests to find out why you have kidney disease. The cause of your kidney disease may affect the type of treatment you receive. 

Too much glucose, also called sugar, in your blood damages your kidneys’ filters. Over time, your kidneys can become so damaged that they no longer do a good job filtering wastes and extra fluid from your blood.

Often, the first sign of kidney disease from diabetes is protein in your urine. When the filters are damaged, a protein called albumin, which you need to stay healthy, passes out of your blood and into your urine. A healthy kidney doesn’t let albumin pass from the blood into the urine.

Diabetic kidney disease is the medical term for kidney disease caused by diabetes.

High blood pressure can damage blood vessels in the kidneys so they don’t work as well. If the blood vessels in your kidneys are damaged, your kidneys may not work as well to remove wastes and extra fluid from your body. Extra fluid in the blood vessels may then raise blood pressure even more, creating a dangerous cycle.

More information is provided in the NIDDK health topic, High Blood Pressure and Kidney Disease.

The most important step you can take to treat kidney disease is to control your blood pressure. High blood pressure can damage your kidneys. You can protect your kidneys by keeping your blood pressure at or less than the goal set by your health care provider. For most people, the blood pressure goal is less than 140/90 mm Hg.

Work with your health care provider to develop a plan to meet your blood pressure goals. Steps you can take to meet your blood pressure goals may include eating heart-healthy and low-sodium meals, quitting smoking, being active, getting enough sleep, and taking your medicines as prescribed.

To reach your blood glucose goal, check your blood glucose level regularly. Use the results to guide decisions about food, physical activity, and medicines. Ask your health care provider how often you should check your blood glucose level.

Your health care provider will also test your A1C. The A1C is a blood test that measures your average blood glucose level over the past 3 months. This test is different from the blood glucose checks you do regularly. The higher your A1C number, the higher your blood glucose levels have been during the past 3 months. Stay close to your daily blood glucose numbers to help you meet your A1C goal.

The A1C goal for many people with diabetes is below 7 percent. Ask your health care provider what your goal should be. Reaching your goal numbers will help you protect your kidneys. Learn more about how to manage diabetes.

You can protect your kidneys by preventing or managing health conditions that cause kidney damage, such as diabetes and high blood pressure. The steps described below may help keep your whole body healthy, including your kidneys.

During your next medical visit, you may want to ask your health care provider about your kidney health. Early kidney disease may not have any symptoms, so getting tested may be the only way to know your kidneys are healthy. Your health care provider will help decide how often you should be tested.

See a provider right away if you develop a urinary tract infection (UTI), which can cause kidney damage if left untreated.

Choose foods that are healthy for your heart and your entire body: fresh fruits, fresh or frozen vegetables, whole grains, and low-fat or fat-free dairy products. Eat healthy meals and cut back on salt and added sugars. Aim for less than 2,300 milligrams of sodium each day. Try to have less than 10 percent of your daily calories come from added sugars.

Be active for 30 minutes or more on most days. If you are not active now, ask your health care provider about the types and amounts of physical activity that are right for you. Add more activity to your life with these tips to help you get active.