Kidney Disease Overview

Chronic kidney disease means that the kidneys aren't removing waste and excess water from the blood as efficiently as they should. The most common causes of chronic kidney disease are diabetes and high blood pressure.

What Is It?

You have a pair of kidneys that can be found below your ribcage (in the middle of your back), with one sitting on each side of your backbone. Each kidney is the shape of a bean and is the size of a fist, although some also liken them to the size of a computer mouse.

These organs have an enormous job to do. Every half hour, nephrons—the tiny structures within kidneys—clean all of your blood by removing waste and excess fluids, which is then excreted out as urine. Kidneys also play a role in the production of red blood cells, vitamin production, and blood pressure regulation.

Unfortunately, for many people, the kidneys become damaged, and this vital process begins to break down. About 37 million adults in the US have chronic kidney disease, which is also referred to as renal disease. Kidney disease is the ninth leading cause of death in the US.

Types

Chronic Kidney Disease (CKD): A condition where kidney function is gradually lost and can result in complications such as high blood pressure, anemia, bone problems, heart disease, among others. Eventually, CKD can lead to kidney failure, which can be deadly without treatment such as dialysis or a kidney transplant.

Kidney Cancer: When cancer begins in the kidney, it's referred to as kidney cancer. This cancer is diagnosed in more than 75,000 men and women each year and affects more men than women. The average age of diagnosis is 64.

Kidney Cysts: These are fluid-filled sacs in the kidneys, which can be caused by diseases like polycystic kidney disease (PKD). PKD impairs kidney function and can lead to kidney failure. Another type is acquired cystic kidney disease (ACKD), a complication of chronic kidney disease.

Kidney Stones: The build-up of wastes in your blood can form kidney stones, which are most common in non-Hispanic white people and men. Smaller stones may be asymptomatic, but larger ones can cause extreme pain while urinating, blood in your urine, lower back pain, and nausea and vomiting.

Kidney Infections: A kidney infection is a type of urinary tract infection (UTI) called pyelonephritis. It's caused by bacteria or a virus that infects one or both kidneys and requires antibiotic treatment.

Glomerulonephritis (GN): Each nephron contains filters called glomeruli, which are tiny blood vessels. Inflammation and damage to glomeruli is called glomerulonephritis, which can lead to blood clots, chronic kidney disease, and kidney failure.

IgA Nephropathy: Immunoglobulin A nephropathy, or Berger's disease, is when deposits of the IgA antibody build up in the kidneys. The condition has no cure, so the treatment is focused on slowing progression of kidney damage.

Symptoms

Most adults who have kidney disease are unaware that they do. Depending on what type of kidney disease you have, you may have varying symptoms.

The following are symptoms for chronic kidney disease, which usually only appear during advanced stages of the disease, when kidneys have lost most of their ability to function (called kidney failure). This is why many people who have CKD don't know it.

• Anemia.
• Fatigue.
• Headache.
• Loss of appetite and weight loss.
• Trouble sleeping.
• Muscle cramps.
• Swelling in legs, ankles, feet, face (especially the eyes), and hands.
• Dry, itchy skin.
• Urinary changes: Increased urination, bubbly/foamy urine, darker urine, or blood in the urine.
• Cognitive problems, e.g., reduced ability to focus, memory problems, and dizziness.
• Bad breath or a metallic taste in the mouth.
• Nausea and vomiting.
• Chest pain.
• Shortness of breath.

Causes

One-third of adults in the US are at risk for kidney disease. That's because diabetes and high blood pressure, two of the most common risk factors for CKD, are so prevalent among American adults. Diabetes and hypertension account for three-fourths of new diagnoses of CKD.

• Diabetes is a condition where your blood sugar is too high, which make kidneys work overtime to filter blood. Diabetes also damages blood vessels.

• High blood pressure causes damage to blood vessels, stymying the flow of oxygen and nutrients to nephrons, which ultimately impairs their blood-filtering ability. Hypertension can also eventually narrow or weaken the arteries around kidneys, preventing adequate blood flow to the organs.

Other causes of kidney disease include genetics, malformations during fetal development, autoimmune disorders such as lupus, chronic UTIs, and kidney stones or tumors.

Diagnosis

When kidneys are beginning to be damaged, it's likely you won't experience any symptoms. That's why your kidney function should be tested if you have conditions that put you at risk for kidney disease, including diabetes, high blood pressure, heart disease, and a family history of heart failure. Your doctor will recommend two or three tests:

• Blood Test for GFR: This blood test looks at your glomerular filtration rate. (Remember, these are the clusters of small blood vessels that filter your blood.) A healthy GFR is 60 or more.

• Blood Test for Creatinine: This blood test can be a marker for severity of kidney disease.

• Urine Test for Albumin: Albumin is a protein marker in the urine that signals kidney damage.

In addition, your doctor may recommend other tests:

• Imaging: An ultrasound or CT scan can provide an image of your kidneys to assess their size and look for kidney stones or tumors.

• Biopsy: A kidney biopsy may be used to determine the cause and severity of your kidney disease.

Treatment

Unfortunately, damage to the kidneys is permanent. But being diagnosed early can prevent kidney failure. For CKD, the goal of treatment is to stop further kidney damage in order to prevent the progression of the disease. You can do this by:

Blood Pressure Control: Maintaining healthy blood pressure or bringing down blood pressure to the healthy range.

Blood Glucose management: Proper treatment for prediabetes or diabetes will keep blood sugar levels stable.

Symptom Management: To relieve symptoms and complications that arise from later-stage kidney disease, your doctor may prescribe medications to treat anemia, fluid retention, and weak bones.

Diet Changes: If you have CKD, your doctor will recommend a low-sodium, heart-healthy diet that emphasizes smaller portions of proteins. Depending on your kidney function, you may also have to limit the amount of phosphorus and potassium in your diet.

Dialysis: When your kidneys have lost more than 85 percent of their ability to function to remove waste from your blood, you have kidney failure, which is life-threatening. Kidney failure can be treated with dialysis, which sends your blood through a filter outside of your body; cleaned blood is then returned to your body. This procedure can be done in a dialysis center or at home.

Kidney Transplant: A surgical procedure where a healthy donor kidney is placed into your body. While transplant can help you feel better, it is not a cure for kidney failure.

Prevention

Kidney disease prevention starts with healthy lifestyle habits that keep your blood pressure and blood glucose levels in check, including:

• A healthy diet that focuses on whole, minimally processed foods, e.g., vegetables, fruits, whole grains, legumes, nuts and seeds, lean protein, fish and heart-healthy sources of fat like olive oil. Stick to the recommended sodium limit and consume no more than 2,300 mg per day.
• Regular exercise can help you maintain a healthy weight and improve blood flow throughout your body.
• Get seven to eight hours of sleep per night
• Don't smoke and drink alcohol moderately if you consume alcohol. (One drink per day for women and two for men, max.)

If you already have hypertension or diabetes, you'll want to follow your doctor's advice on managing those conditions—through treatments like lifestyle changes and medication—to prevent their complications, which includes the development of chronic kidney disease. If you have a UTI or kidney stones, see your doctor for appropriate treatment.

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