The kidneys play key roles in body function. Your kidneys have a range of important functions in your body:
- Filtering the blood and getting rid of waste products
- Balancing the electrolyte levels in the body
- Controlling blood pressure
- Stimulating the production of red blood cells
The kidneys are found in the abdomen toward the back, normally one on each side of the spine. The renal arteries supply blood directly from the aorta and blood is sent back to the heart via the renal veins to the vena cava.
Your kidneys can monitor the amount of body fluid, the concentrations of electrolytes like sodium and potassium as well as the acid-base balance of the body.
The kidneys filter waste products of body metabolism such as urea from protein metabolism and uric acid from DNA breakdown. Two waste products in the blood are usually measure:
- Blood urea nitrogen (BUN)
- Creatinine (Cr)
Sensors within specialized kidney cells regulate how much water to excrete as urine when blood flows to the kidney, along with what concentration of electrolytes. For instance, when an individual is dehydrated from exercise or from an illness, the kidneys will hold as much water as possible. This causes the urine to become concentrated.
The urine is much more dilute when adequate water is present in the body and the urine becomes clear. This system is controlled by renin (a hormone produced in the kidney) that is part of the fluid and blood pressure regulation systems.
Kidneys produces a hormone known as erythropoietin, it stimulates bone marrow to make red blood cells. Special cells in the kidney monitor oxygen concentration in blood. When oxygen levels fall, the erythropoietin level rises and the body starts to manufacture more red blood cells.
Urine produced by each kidney flows through the ureter. Urine is then stored within the bladder and when urination occurs, the bladder disposes urine through the urethra.
Why does kidney failure occur?
Kidney failure occurs when the kidneys lose the ability to filter waste from the blood sufficiently. Many factors may interfere with your kidney health and function such as:
- Toxic exposure to environmental pollutants
- Certain acute and chronic diseases
- Severe dehydration
- Kidney trauma
The human body becomes overloaded with toxins when the kidneys can’t do their job. This will eventually lead to kidney failure and may even be life-threatening if it’s left untreated.
What Causes Kidney Failure?
People who are at highest risk for kidney failure usually suffer from one or more of the following causes:
- Loss of Blood Flow to the Kidneys: Sudden loss of blood flow to the kidneys can cause kidney failure. Some conditions and diseases that may cause loss of blood flow to the kidneys are:
- A heart attack
- Heart disease
- Scarring of the liver or liver failure
- A severe burn
- An allergic reaction
- A severe infection (such as sepsis)
- Consuming blood pressure and anti-inflammatory medications may also limit blood flow.
- Urine Elimination Problems: Toxins build up and overload the kidneys when your body can’t eliminate urine. Sometimes, certain cancers can also block the urine passageways. These cancers include prostate (most common type in men), colon, cervical, and bladder cancers. Other conditions that may interfere with urination and possibly lead to kidney failure are:
- Kidney stones
- An enlarged prostate
- Blood clots within your urinary tract
- Damage to the nerves that control your bladder
- Other Causes
Some diseases and conditions that may lead to kidney failure are:
- Blood clots in or around your kidneys
- Overload of toxins from heavy metals
- Drugs and alcohol
- Vasculitis (which is an inflammation of blood vessels)
- Lupus ( autoimmune disease that can cause inflammation of many body organs)
- Glomerulonephritis (inflammation of the small blood vessels of the kidneys)
- Haemolytic uremic syndrome (breakdown red blood cells following a bacterial infection, usually of the intestines)
- Multiple myeloma (cancer of the plasma cells in your bone marrow
- scleroderma, which is an autoimmune disease that affects your skin)
- Thrombotic thrombocytopenic purpura (a disorder that causes blood clots in small vessels)
- Chemotherapy drugs (medications that treat cancer and some autoimmune diseases)
- Dyes used in some imaging tests
- Certain antibiotics
There are five different types of kidney failure:
- Acute Prerenal Kidney Failure: When there is insufficient blood flow to the kidneys, it can cause acute prerenal kidney failure. The kidneys will not be able to filter toxins from the blood. It can usually be cured once the cause of the decreased blood flow is determined.
- Acute Intrinsic Kidney Failure: May be caused by direct trauma to the kidneys such as physical impact or an accident.Some of the causes may also include toxin overload and ischemia (which is a lack of oxygen to the kidneys). Ischemia could be caused by:
- Severe bleeding
- Renal blood vessel obstruction
- Chronic Pre-renal Kidney Failure: Occurs when there isn’t enough blood flowing to the kidneys for an extended period of time. The kidneys will begin to shrink and lose the ability to function.
- Chronic Intrinsic Kidney Failure: When there is long-term damage to the kidneys due to intrinsic kidney disease. This is caused by a direct trauma to the kidneys such as severe bleeding or a lack of oxygen.
- Chronic Post-Renal Kidney Failure: Long-term blockage of the urinary tract that prevents urination. This in turn causes pressure and eventually lead to kidney damage.
SYMPTOMS OF KIDNEY FAILURE
Chronic kidney disease (CKD) normally worsen slowly. The symptoms may not show up until the kidneys are severely damaged.
You may notice symptoms that are caused by waste and extra fluid building up in the body in the late stages as you are nearing kidney failure (ESRD).
When your kidneys are beginning to fail, you may notice 1 or more of the following symptoms:
- Muscle cramps
- Nausea and vomiting
- Not feeling hungry
- Swelling (feet and ankles)
- Too much urine or not enough urine
- Trouble catching your breath
- Trouble sleeping
When the kidneys stop working suddenly (acute kidney failure), these symptoms may be experienced:
- Abdominal pain
- Back pain
If you experience 1 or more of any of the symptoms above, it may be a sign of serious kidney problems.
What are my treatment options for kidney failure?
You have three possible blood filtering treatment options to choose from. There is also a fourth option that offers care without replacing the work of the kidneys. Unfortunately, none of these treatments helps the kidneys get better. However, they all can help you feel better.
What should I know about hemodialysis?
Purpose of Hemodialysis
The purpose of hemodialysis is to filter your blood. This type of dialysis uses a machine to replicate the removal of any harmful wastes and extra fluid, as your kidneys would have done when they were healthy. Hemodialysis helps control blood pressure and balance important minerals, such as calcium, sodium, potassium, and bicarbonate, in your blood. Hemodialysis is not a cure for kidney failure; however, it can help you feel better and ultimately live longer.
How Hemodialysis Works
Before you can begin dialysis, a surgeon will create a vascular access, usually in your arm. A vascular access lets high volumes of blood flow continuously during your hemodialysis treatment to filter as much blood has possible per treatment.
Hemodialysis uses a machine to move your blood through a filter, called a dialyzer, outside your body. A pump on the hemodialysis machine draws your blood through a needle into a tube, a few ounces at a time. Your blood then travels through the tube, which takes it to the dialyzer. Inside the dialyzer, your blood flows through thin fibers that filter out any waste and extra fluid. After the dialyzer filters your blood, another tube carries your blood back into your body.
What should I know about peritoneal dialysis?
Purpose of Peritoneal Dialysis
The purpose of peritoneal dialysis is to filter waste and extra fluid from your body. This type of dialysis utilizes the lining of your belly—the space in your body that holds your stomach, bowels, and liver—to filter your blood. This lining – also called the peritoneum –replicates the work of your kidneys.
How Peritoneal Dialysis Works
A doctor will place a soft tube, called a catheter, in your belly a few weeks before your scheduled to start treatment and will stay in your belly permanently. When you start peritoneal dialysis, you will empty a special dialysis solution, from a plastic bag through the catheter into your belly. When the bag is empty, you can disconnect your catheter from the bag so you can move around and do your normal activities. While the dialysis solution is inside your belly, it soaks up wastes and extra fluid from your body until you drain your dialysisa few hours later, through another tube into a drain bag. You can get rid of the used dialysis solution, now filled with wastes and extra fluid, by flushing it down the toilet or down emptying it down the drain of your bathtub. Then you start over with a fresh bag of dialysis solution. The process of emptying the used dialysis solution and refilling your belly with fresh solution is referred to as an exchange. The process goes on continuously, so you always have dialysis solution in your belly soaking up wastes and extra fluid from your body.
Types of Peritoneal Dialysis
There are two types of peritoneal dialysis available. After you have learned about the types of peritoneal dialysis, you can choose the type that best fits your lifestyle. If one schedule or type of peritoneal dialysis does not suit you, talk with your doctor about trying the other type.
- Continuous ambulatory peritoneal dialysis: This does not require a machine and you can do it in any clean, well-lit place. The time period that the dialysis solution is in your belly is called the dwell time. With continuous ambulatory peritoneal dialysis, the dialysis solution stays in your belly for a dwell time of 4 to 6 hours(or longer in some cases). The process of draining the used dialysis solution and replacing it with fresh solution takes about 30 to 40 minutes. Most people change the dialysis solution at least four times a day and sleep with solution in their belly at night. With continuous ambulatory peritoneal dialysis, you do not have to wake up and perform dialysis tasks during the night.
- Continuous cycler-assisted peritoneal dialysis: This uses a machine called a cycler to fill and empty your belly three to five times during the night while you sleep. In the morning, you begin one exchange with a dwell time that lasts the entire day. You may do an additional exchange in the middle of the afternoon without the cycler to increase the amount of waste removed and to reduce the amount of fluid left behind in your body.
Is dialysis a cure for kidney failure?
No. Hemodialysis and peritoneal dialysis help you feel better and live longer; however, they do not cure kidney failure. Although people with kidney failure are now living longer than before, over the years kidney disease can cause other problems, such as heart disease, bone disease, arthritis, nerve damage, infertility, and malnutrition. These problems won’t be fixed by going on dialysis; however, doctors now have new and better ways to treat and prevent these conditions. You should discuss these conditions and their treatments with your doctor.
This surgery involves placing a healthy kidney from a person who has just died or a living person – usually a family member – into your body to take over the job of filtering your blood. Another treatment option is a kidney transplant, but there’s usually a long waiting list in order to receive a donor kidney that’s compatible with your body. The advantages of a transplant are that the new kidney can work perfectly, rendering dialysis no longer necessary. The disadvantage is that immunosuppressive drugs must be taken after the surgery. These drugs have their own list of side effects, some of which are quite serious. There is also a risk that transplant surgery may fail and may even be life-threatening.
What should I know about kidney transplantation?
The purpose of kidney transplantation is to surgically place a healthy kidney from a suitable donor—a person who has just died or a living person, most often a family member—into your body. A kidney from someone who has just died is know as a deceased donor kidney. A kidney from a living person is known as a living donor kidney. A functioning kidney transplant is more effective at filtering wastes and keeping you healthy than dialysis.
How Kidney Transplantation Works
In most cases, surgeonsplace transplanted kidneys in the lower front part of your abdomen, where the kidney is then connected to an artery, which brings unfiltered blood into the kidney, and a vein, which takes filtered blood out of the kidney. The surgeon also transplants the ureter from the donor to let urine from the new kidney flow to your bladder. Unless your damaged kidneys cause issues such as infection, they can remain inside your body in their normal position. The transplanted kidney takes over the job of filtering your blood. Because your body will normally attack anything it sees as foreign, it is essential to keep your body from attacking the newly transplanted kidney. To prevent your body attacking your new kidney you will need to take medicines called immunosuppressant’s for as long as the transplanted kidney is functioning inside your body.
- Conservative management: The choice not to treat kidney failure with dialysis or a transplant. Instead, the focus is on using medicines to keep you feeling comfortable while preserving kidney function through diet, and treating the problems of kidney failure, such as anemia—a shortage of red blood cells that can cause constant fatigue—and weak bones.
DIAGNOSING KIDNEY FAILURE
There are several tests that can be used to diagnose kidney failure. These include:
- Urinalysis: Urinalysis is the testing of a urine sample for any abnormalities, including abnormal protein or sugar that spills into the urine. Your doctor may perform a urinary sediment examination, which will measure the amount of red and white blood cells, look for high levels of bacteria, and search for high numbers of cellular casts.
- Urine Volume Measurements: Measuring urine output is an easy and effective test to help diagnose kidney failure. For example, low urinary output may suggest that kidney disease is due to a urinary blockage, which can be caused by multiple injuries or illnesses.
- Blood Samples: Samples of your blood are taken to measure substances that your kidneys are responsible for filtering, such as blood urea nitrogen (BUN) and creatinine (Cr). A rapid rise in their levels may indicate acute kidney failure.
- Imaging: Imaging tests such as ultrasounds, MRI, and CT scans provide images of the kidneys and urinary tract. This allows your doctor to look for any blockages or abnormalities in your kidneys.
- Kidney Tissue Sample: Tissue samples are examined for any abnormal deposits, scarring, or infectious organisms. A kidney biopsy is a simple procedure that is often used to collect the tissue sample, and is usually performed while your awake. A local anesthetic is used to eliminate any discomfort. The sample is collected with a biopsy needle inserted through your skin and down into the kidney. X-ray or ultrasound equipment is used to locate the kidneys and assist the doctor in guiding the needle.