Chronic kidney disease is the slow loss of kidney function over time. The main function of the kidneys is to remove wastes and excess water from the body.
Chronic kidney disease (CKD) slowly gets worse over time. In the early stages, there may be no symptoms. The loss of function usually takes months or years to occur. It may be so slow that symptoms do not occur until kidney function is less than one-tenth of normal.
The final stage of chronic kidney disease is called end-stage renal disease (ESRD). The kidneys no longer function and the patient needs dialysis or a kidney transplant.
Chronic kidney disease and ESRD affect more than 2 out of every 1,000 people in the United States.
Diabetes and high blood pressure are the two most common causes and account for most cases.
Many other diseases and conditions can damage the kidneys, including:
- Problems with the arteries leading to or inside the kidneys
- Birth defects of the kidneys (such as polycystic kidney disease)
- Some pain medications and other drugs
- Certain toxic chemicals
- Autoimmune disorders (such as systemic lupus erythematosus and scleroderma)
- Injury or trauma
Kidney stones and infection
Reflux nephropathy (in which the kidneys are damaged by the backward flow of urine into the kidneys)
- Other kidney diseases
Chronic kidney disease leads to a buildup of fluid and waste products in the body. This condition affects most body systems and functions, including red blood cell production, blood pressure control, and vitamin D and bone health.
The early symptoms of chronic kidney disease often occur with other illnesses, as well. These symptoms may be the only signs of kidney disease until the condition is more advanced.
Symptoms may include:
General ill feeling and fatigue
- Generalized itching (pruritus) and dry skin
Weight loss without trying to lose weight
- Appetite loss
Other symptoms that may develop, especially when kidney function has worsened:
Abnormally dark or light skin
- Bone pain
- Brain and nervous system symptoms
Drowsiness and confusion
- Problems concentrating or thinking
Numbness in the hands, feet, or other areas
Muscle twitching or cramps
- Easy bruising, bleeding, or blood in the stool
- Frequent hiccups
- Low level of sexual interest and impotence
- Menstrual periods stop (amenorrhea)
- Sleep problems, such as insomnia, restless leg syndrome, and obstructive sleep apnea
- Swelling of the feet and hands (edema)
- Vomiting, typically in the morning
Exams and Tests
High blood pressure is almost always present during all stages of chronic kidney disease. A neurologic examination may show signs of nerve damage. The health care provider may hear abnormal heart or lung sounds with a stethoscope.
A urinalysis may show protein or other changes. These changes may appear 6 months to 10 or more years before symptoms appear.
Tests that check how well the kidneys are working include:
Chronic kidney disease changes the results of several other tests. Every patient needs to have the following checked regularly, as often as every 2 - 3 months when kidney disease gets worse:
Complete blood count (CBC)
Causes of chronic kidney disease may be seen on:
Abdominal CT scan
This disease may also change the results of the following tests:
Bone density test
Controlling blood pressure is the key to delaying further kidney damage.
- Angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) are used most often.
- The goal is to keep blood pressure at or below 130/80 mmHg
Other tips for protecting the kdineys and preventing heart disease and stroke:
- Do not smoke.
- Eat meals that are low in fat and cholesterol
- Get regular exercise (talk to your doctor or nurse before starting).
- Take drugs to lower your cholesterol, if necessary.
- Keep your blood sugar under control.
Always talk to your kidney doctor before taking any over-the-counter medicine, vitamin, or herbal supplement. Make sure all of the doctors you visit know you have chronic kidney disease.
Other treatments may include:
- Special medicines called phosphate binders, to help prevent phosphorous levels from becoming too high
- Treatment for anemia, such as extra iron in the diet, iron pills, special shots of a medicine called erythropoietin, and blood transfusions
- Extra calcium and vitamin D (always talk to your doctor before taking)
You may need to make changes in your diet. See: Diet for chronic kidney disease for more details.
- You may need to limit fluids.
- Your health care provider may recommend a low-protein diet.
- You may have to restrict salt, potassium, phosphorous, and other electrolytes.
- It is important to get enough calories when you are losing weight.
Different treatments are available for problems with sleep or restless leg syndrome.
Everyone with chronic kidney disease should be up-to-date on important vaccinations, including:
Pneumococcal polysaccharide vaccine (PPV)
H1N1 (swine flu) vaccine
Hepatitis B vaccine
Hepatitis A vaccine
When loss of kidney function becomes more severe, you will need to prepare for dialysis or a kidney transplant.
- When you start dialysis depends on different factors, including your lab test results, severity of symptoms, and readiness.
- You should begin to prepare for dialysis before it is absolutely necessary. The preparation includes learning about dialysis and the types of dialysis therapies, and placement of a dialysis access.
- Even those who are candidates for a kidney transplant will need dialysis while waiting for a kidney to become available.
See: Kidney disease - support group
Many people are not diagnosed with chronic kidney disease until they have lost much of their kidney function.
There is no cure for chronic kidney disease. Untreated, it usually progresses to end-stage renal disease. Lifelong treatment may control the symptoms of chronic kidney disease.
- Bleeding from the stomach or intestines
- Bone, joint, and muscle pain
- Changes in blood sugar
- Damage to nerves of the legs and arms (peripheral neuropathy)
- Fluid buildup around the lungs (pleural effusion)
- Heart and blood vessel complications
Congestive heart failure
Coronary artery disease
- High blood pressure
- High phosphorous levels
High potassium levels
- Increased risk of infections
- Liver damage or failure
Miscarriages and infertility
- Weakening of the bones and increased risk of fractures
Treating the condition that is causing the problem may help prevent or delay chronic kidney disease. People who have diabetes should control their blood sugar and blood pressure levels and should not smoke.
Kidney failure - chronic; Renal failure - chronic; Chronic renal insufficiency; Chronic kidney failure; Chronic renal failure