Chronic Kidney Disease

Definition

Chronic kidney disease, also called chronic kidney failure, describes the gradual loss of kidney function. Your kidneys filter wastes and excess fluids from your blood, which are then excreted in your urine. When chronic kidney disease reaches an advanced stage, dangerous levels of fluid, electrolytes and wastes can build up in your body.

In the early stages of chronic kidney disease, you may have few signs or symptoms. Chronic kidney disease may not become apparent until your kidney function is significantly impaired.

Treatment for chronic kidney disease focuses on slowing the progression of the kidney damage, usually by controlling the underlying cause. Chronic kidney disease can progress to end-stage kidney failure, which is fatal without artificial filtering (dialysis) or a kidney transplant.

Symptoms

Signs and symptoms of chronic kidney disease develop over time if kidney damage progresses slowly. Signs and symptoms of kidney disease may include:

• Nausea
• Vomiting
• Loss of appetite
• Fatigue and weakness
• Sleep problems
• Changes in urine output
• Decreased mental sharpness
• Muscle twitches and cramps
• Hiccups
• Swelling of feet and ankles
• Persistent itching
• Chest pain, if fluid builds up around the lining of the heart
• Shortness of breath, if fluid builds up in the lungs
• High blood pressure (hypertension) that's difficult to control

Signs and symptoms of kidney disease are often nonspecific, meaning they can also be caused by other illnesses. And because your kidneys are highly adaptable and able to compensate for lost function, signs and symptoms may not appear until irreversible damage has occurred.

When to see a doctor

Make an appointment with your doctor if you have any signs or symptoms of kidney disease.

If you have a medical condition that increases your risk of chronic kidney disease, your doctor is likely to monitor your blood pressure and kidney function with urine and blood tests during regular office visits. Ask your doctor whether these tests are necessary for you.

Causes

Chronic kidney disease occurs when a disease or condition impairs kidney function, causing kidney damage to worsen over several months or years.

Diseases and conditions that commonly cause chronic kidney disease include:

• Type 1 or type 2 diabetes
• High blood pressure
• Glomerulonephritis (gloe-mer-u-lo-nuh-FRY-tis), an inflammation of the kidney's filtering units (glomeruli)
• Interstitial nephritis, an inflammation of the kidney's tubules and surrounding structures
• Polycystic kidney disease
• Prolonged obstruction of the urinary tract, from conditions such as enlarged prostate, kidney stones and some cancers
• Vesicoureteral (ves-ih-koe-yoo-REE-ter-ul) reflux, a condition that causes urine to back up into your kidneys
• Recurrent kidney infection, also called pyelonephritis (pie-uh-lo-nuh-FRY-tis)

Risk factors

Factors that may increase your risk of chronic kidney disease include:

• Diabetes
• High blood pressure
• Heart disease
• Smoking
• Obesity
• High cholesterol
• Being African-American, Native American or Asian-American
• Family history of kidney disease
• Age 65 or older

Complications

Chronic kidney disease can affect almost every part of your body. Potential complications may include:

• Fluid retention, which could lead to swelling in your arms and legs, high blood pressure, or fluid in your lungs (pulmonary edema)
• A sudden rise in potassium levels in your blood (hyperkalemia), which could impair your heart's ability to function and may be life-threatening
• Heart and blood vessel disease (cardiovascular disease)
• Weak bones and an increased risk of bone fractures
• Anemia
• Decreased sex drive or impotence
• Damage to your central nervous system, which can cause difficulty concentrating, personality changes or seizures
• Decreased immune response, which makes you more vulnerable to infection
• Pericarditis, an inflammation of the sac-like membrane that envelops your heart (pericardium)
• Pregnancy complications that carry risks for the mother and the developing fetus
• Irreversible damage to your kidneys (end-stage kidney disease), eventually requiring either dialysis or a kidney transplant for survival

Tests and diagnosis

To determine whether you have chronic kidney disease, you may need tests and procedures such as:

• Blood tests. Kidney function tests look for the level of waste products, such as creatinine and urea, in your blood.
• Urine tests. Analyzing a sample of your urine may reveal abnormalities that point to chronic kidney failure and help identify the cause of chronic kidney disease.
• Imaging tests. Your doctor may use ultrasound to assess your kidneys' structure and size. Other imaging tests may be used in some cases.
• Removing a sample of kidney tissue for testing. Your doctor may recommend a kidney biopsy to remove a sample of kidney tissue. Kidney biopsy is often done with local anesthesia using a long, thin needle that's inserted through your skin and into your kidney. The biopsy sample is sent to a lab for testing to help determine what's causing your kidney problem.

Lifestyle and home remedies

As part of your treatment for chronic kidney disease, your doctor may recommend a special diet to help support your kidneys and limit the work they must do. Ask your doctor for a referral to a dietitian who can analyze your current diet and suggest ways to make your diet easier on your kidneys.

Depending on your situation, kidney function and overall health, your dietitian may recommend that you:

• Avoid products with added salt. Lower the amount of sodium you eat each day by avoiding products with added salt, including many convenience foods, such as frozen dinners, canned soups and fast foods. Other foods with added salt include salty snack foods, canned vegetables, and processed meats and cheeses.
• Choose lower potassium foods. Your dietitian may recommend that you choose lower potassium foods at each meal. High-potassium foods include bananas, oranges, potatoes, spinach and tomatoes. Examples of low-potassium foods include apples, cabbage, carrots, green beans, grapes and strawberries. Be aware that many salt substitutes contain potassium, so you should avoid them if you have kidney failure.
• Limit the amount of protein you eat. Your dietitian will estimate the appropriate number of grams of protein you should eat each day and make recommendations based on that amount. High-protein foods include lean meats, eggs, milk, cheese and beans. Low-protein foods include vegetables, fruits, breads and cereals.

Prevention

To reduce your risk of chronic kidney disease:
• Drink alcohol in moderation, if at all. If you choose to drink alcohol, do so in moderation. For healthy adults, that means no more than one drink a day for women of all ages and men older than 65, and no more than two drinks a day for men 65 and younger.
• Follow instructions on over-the-counter medications.When using nonprescription pain relievers, such as aspirin, ibuprofen (Advil, Motrin IB, others) and acetaminophen (Tylenol, others), follow the instructions on the package. Taking too many pain relievers could lead to kidney damage and generally should be avoided if you have kidney disease. Ask your doctor whether these drugs are safe for you.
• Maintain a healthy weight. If you're at a healthy weight, work to maintain it by being physically active most days of the week. If you need to lose weight, talk with your doctor about strategies for healthy weight loss. Often this involves increasing daily physical activity and reducing calories.
• Don't smoke. If you're a smoker, talk to your doctor about strategies for quitting smoking. Support groups, counseling and medications can all help you to stop.
• Manage your medical conditions with your doctor's help. If you have diseases or conditions that increase your risk of kidney disease, work with your doctor to control them. Ask your doctor about tests to look for signs of kidney damage.
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