Kidney Disease / Chronic Kidney Disease
What is kidney disease?
Having kidney disease means that there is damage to your kidneys and they aren’t working as well as they should. Kidney disease is called “chronic” because kidney function slowly gets worse over time. Kidney disease leads to kidney failure, which is also called end-stage kidney disease. At this point, you’ll need dialysis (artificial filtering) or a kidney transplant.
What do your kidneys do?
You have two kidneys. They are bean-shaped organs that are located toward your back, on either side of your spine, just underneath the rib cage. Each kidney is about the size of your fist.
Your kidneys have many jobs, but their main job is to filter (clean) your blood, getting rid of toxins (wastes) and excess salt and water as urine. If your kidneys are damaged and don’t work as they should, wastes can build up in your blood and can make you sick. Your kidneys also balance the amount of salts and minerals in your body, make hormones that control blood pressure, make red blood cells and keep your bones strong.
Are there stages of chronic kidney disease?
Yes, there are five stages of kidney disease. The stages are based on how well your kidneys are able to do their job – to filter out waste and extra fluid from your blood. The stages range from very mild (stage 1) to kidney failure (stage 5). Healthcare providers determine the stage of your kidney function according to the glomerular filtration rate (GFR). Your GFR is a number based on the amount of creatinine, a waste product, found in your blood, along with other factors including your age, race and gender.
|Stages of Chronic Kidney Disease|
|Stage||GFR* (ml/min)||What it Means|
|Stage 1||90 and higher||Your kidneys are working well but you have signs of mild kidney damage.|
|Stage 2||60 to 89||Your kidneys are working well but you have more signs of mild kidney damage|
|Stage 3||30 to 59||Your kidneys aren’t working as well as they should and you have moderately decreased kidney function. This is the most common stage. You may notice symptoms at this stage.|
|Stage 4||15 to 29||You have poor kidney function; your kidneys are moderately to severely damaged.|
|Stage 5||Less than 15||Your kidneys are very close to failing or have failed. You need kidney dialysis or a kidney transplant.|
|*GFR = glomerular filtration rate|
Who is at risk for chronic kidney disease?
Some 37 million people in the United States are living with chronic kidney disease. Anyone can get chronic kidney disease. You are more at risk for chronic kidney disease if you:
- Have diabetes.
- Have high blood pressure.
- Have heart disease.
- Have a family history of kidney disease.
- Have abnormal kidney structure.
- Are African-American, Hispanic, Native American or Asian.
- Are over 60 years of age.
- Have a long history of taking painkillers, including over-the-counter products such as aspirin and ibuprofen.
Symptoms and Causes
What causes kidney disease?
Kidney diseases happen when your kidneys are damaged and can’t filter your blood. The damage can happen quickly – when it’s caused by injury or toxins – or, more commonly, over months or years.
High blood pressure (hypertension) and diabetes are the two most common causes of chronic kidney disease. Other causes and conditions that affect kidney function and can cause chronic kidney disease include:
- Glomerulonephritis. This type of kidney disease involves damage to the glomeruli, which are the filtering units inside your kidneys.
- Polycystic kidney disease. This is a genetic disorder that causes many fluid-filled cysts to grow in your kidneys, reducing the ability of your kidneys to function.
- Hypertensive nephrosclerosis. Kidney damage caused by chronic, poorly controlled hypertension.
- Membranous nephropathy. This is a disorder where your body’s immune system attacks the waste-filtering membranes in your kidney.
- Obstructions of the urinary tract from kidney stones, an enlarged prostate or cancer.
- Vesicourethral reflux. This is a condition in which urine flows backward – refluxes – back up the ureters to the kidneys
- Nephrotic syndrome. This is a collection of symptoms that indicate kidney damage.
- Recurrent kidney infection (pyelonephritis).
- Diabetic nephropathy. This is damage or dysfunction of one or more nerves, caused by diabetes, which typically results in numbness, tingling, muscle weakness and pain in the affected area.
- Lupus and other immune system diseases that cause kidney problems including polyarteritis nodosa, sarcoidosis, Goodpasture syndrome and Henoch-Schonlein purpura.
What are the symptoms of chronic kidney disease?
In the early stages of kidney disease, you usually don’t have noticeable symptoms. As the disease worsens, symptoms may include:
- A need to pee (urinate) more often.
- Tiredness, weakness, low energy level.
- Loss of appetite.
- Swelling of your hands, feet and ankles.
- Shortness of breath.
- Blood in your urine; foamy urine.
- Puffy eyes.
- Dry and itchy skin.
- Trouble concentrating.
- Trouble sleeping
- Nausea or vomiting.
- Muscle cramps.
- High blood pressure.
- Darkening of your skin.
What are the complications of chronic kidney disease?
If your kidneys aren’t working properly, the rest of your body isn’t either. Some of the complications of chronic kidney disease include:
- Low red blood cell count (anemia).
- Weak and brittle bones.
- Metabolic acidosis. This is a chemical imbalance (acid-base) in your blood caused by decrease in kidney function.
- High blood pressure.
- Heart disease, including increased risk of stroke and heart attack.
- High potassium (hyperkalemia), which affects your heart’s ability to function correctly.
- High phosphorus (hyperphosphatemia).
- Fluid buildup, leading to swelling in feet, ankles and hands; fluid in your lungs.
- Erectile dysfunction, fertility problems.
- Decreased immune response, increasing your risk of infection.
Diagnosis and Tests
How is kidney disease diagnosed?
First your healthcare provider will take your medical history, conduct a physical exam, ask about any medication you are currently taking, ask about any symptoms you have noticed, and inquire if any of your family members have kidney disease.
Your healthcare provider will order blood tests, a urine test and will also check your blood pressure.
The blood tests will check:
- Your glomerulofiltration rate (GFR). This describes how efficiently your kidneys are filtering blood – how many milliliters per minute your kidneys are filtering. Your GFR is used to determine the stage of your kidney disease.
- Your serum creatinine level, which tells how well your kidneys are removing this waste product. Creatinine is a waste product from muscle metabolism and is normally excreted in your urine. A high creatinine level in your blood means that your kidneys are not functioning well enough to get rid it in your urine.
A urine protein test will look for the presence of protein (albumin) and blood in your urine. Well-functioning kidneys should not have blood or proteins in your urine. If you do, this means your kidneys are damaged.
Other tests may include imaging tests to look for problems with the size and structure of your kidneys such as ultrasound, magnetic resonance imaging (MRI) and/or computerized tomography (CT) scans. Your healthcare provider may also order a kidney biopsy to check for a specific type of kidney disease or to determine the amount of kidney damage. In this procedure, performed using local anesthesia, a piece of your kidney tissue is removed and examined.
Management and Treatment
How is chronic kidney disease treated?
There is no cure for chronic kidney disease (CKD), but steps may be taken in early CKD to preserve a higher level of kidney function for a longer period of time. If you have reduced kidney function:
- Make and keep your regular healthcare provider / nephrologist (kidney specialist) visits.
- Keep your blood sugar under control (for diabetics).
- Avoid taking painkillers and other medications that may make your kidney disease worse.
- Keep your blood pressure levels under control.
- Consult a dietitian regarding useful changes in diet. Dietary changes may include limiting protein, eating foods that reduce blood cholesterol levels, and limiting sodium (salt) and potassium intake.
- Don’t smoke.
- Treat anemia (if present).
- Exercise/be active on most days of the week.
- Stay at a healthy weight.
What medications are prescribed for people with chronic kidney disease?
Depending on the cause of your kidney disease, you may be prescribed one or more medications. Medications your nephrologist may prescribe include:
- An angiotensin-converting enzyme (ACE) inhibitor or an angiotensin receptor blocker (ARB) to lower your blood pressure.
- A diuretic to help your body eliminate extra fluid.
- Medications to lower cholesterol levels.
- Erythropoetin, to build red blood cells if you are anemic.
- Vitamin D and calcitrol to prevent bone loss.
- Phosphate binder if your kidneys can’t eliminate phosphate.
What is kidney dialysis?
Because there is no cure for CKD, if you are in late-stage disease, you and your healthcare team must consider additional options. Complete kidney failure, left untreated, will result in death. Options for end stages of CKD include dialysis and kidney transplantation.
Dialysis is a procedure that uses machines to remove waste products from your body when your kidneys are no longer able to perform this function. There are two major types of dialysis.
Hemodialysis: With hemodialysis, your blood is circulated through a machine that removes waste products, excess water and excess salt. The blood is then returned to your body. Hemodialysis requires three to four hours, three times a week and is performed at a clinic, hospital or dialysis center.
Peritoneal dialysis: In peritoneal dialysis, a dialysis solution is run directly into your abdomen. The solution absorbs waste and then is removed via catheter. Fresh solution is added to continue the process of cleaning. You can perform this type of dialysis yourself. There are two types of peritoneal dialysis: continuous ambulatory peritoneal dialysis (CAPD), which involves a change in dialysis solution four times a day; and continuous cycling peritoneal dialysis (CCPD). CCPD uses a machine to automatically fill, remove wastes, and refill the fluid during the nighttime.
What is kidney transplantation?
Kidney transplantation involves placing a healthy kidney into your body where it can perform all of the functions that a failing kidney can’t. Kidneys for transplantation come from two sources: living donors and deceased donors. Living donors are usually immediate family members or sometimes spouses. This is possible because a person can live well with one healthy kidney.
Deceased donor kidneys usually come from people who have willed their kidneys before their death by signing organ donor cards. All donors are carefully screened to make sure there is a suitable match and to prevent any transmissible diseases or other complications.
Can kidney disease be prevented?
Seeing your healthcare provider on a regular basis throughout your life is a good start for preventing kidney disease. About one in every three people in the United States is at risk for kidney disease. Identify and manage any risk factors for developing kidney disease.
- Control your high blood pressure. Normal blood pressure is 120/80.
- Control your blood sugar if you have diabetes.
- Eat a healthy diet. Follow a low-fat, low-salt diet.
- Don’t smoke.
- Be active for 30 minutes at least five days a week.
- Maintain a healthy weight.
- Take nonprescription pain relievers only as directed. Taking more than directed can damage your kidneys.
Outlook / Prognosis
What can I expect if I have kidney disease?
If you have kidney disease you can still live a productive home and work life and enjoy time with your family and friends. To have the best outcome possible, it’s important for you to become an active member of your treatment team.
Early detection and appropriate treatment are important in slowing the disease process, with the goal of preventing or delaying kidney failure. You will need to keep your medical appointments, take your medications as prescribed, stick to a healthy diet and monitor your blood pressure and blood sugar.