What is Kidney Disease?
Kidney disease is a general term that can refer to any disorder of the kidneys, but it is usually associated with kidney failure. Also known as renal failure, kidney failure is a condition whereby the kidneys become unable to act in their critical role as one of the main filters of the body. The kidneys are responsible for filtering excessive fluid and toxic wastes from the blood. Life is not possible without functioning kidneys or an artificial system that stands in as a replacement for the kidneys.
You have two kidneys, and they are bean-shaped organs about the size of a fist that are located in the back of your body, behind the upper abdomen, with one on each side of your spine. These organs are one of the true workhorses of the body. They filter and process about 50 gallons of fluid in the bloodstream on a daily basis, day in and day out. Toxins and unneeded fluids are filtered out and removed from the body in the form of urine, and other useful substances are identified and put back into the bloodstream after running through the kidney’s filtration system.
There are two main types of kidney failure that can occur: Acute and Chronic.
- Acute kidney failure happens when the kidneys are damaged by an existing illness, a traumatic injury, or an infection. It is characterized by a sudden loss of kidney function that is most often temporary and reversible. Most cases of acute kidney failure occur while a person is already hospitalized after an accident or major surgery.
- Chronic kidney failure typically comes on slowly over time, and may have few or no symptoms until the disease is fairly far advanced. The most common causes of chronic kidney failure are hypertension (high blood pressure) and diabetes. Chronic kidney failure is permanent and irreversible. Eventually the disease will advance to End-Stage Renal Disease (ESRD), at which point the only options for the patient to remain alive are artificial filtering of the blood (dialysis), or a kidney transplant.
What Are the Causes of Kidney Failure?
When oxygenated blood leaves the heart to travel to the rest of the body, one of the first legs of the journey is a trip through the kidneys. From the renal arteries, the blood proceeds through the nephrons, which are the actual filtering mechanisms of the kidney. Each kidney has approximately one million nephrons, and this is where the blood is sorted to separate the toxins from the good stuff. Waste products such as urea, uric acid, and creatinine are steered towards the urine and transported out of the body. Other substances such as sugars, minerals, and amino acids are redirected back into the bloodstream and delivered as nutrients to the body. When this complex system breaks down, these essential tasks are done insufficiently, and kidney failure occurs.
Acute Kidney Failure:
The acute form of renal disease often develops very quickly with no apparent warning. It is commonly associated with other critical illnesses such as a heart attack or stroke, and its cause is sometimes considered to be a consequence or side effect of the main condition. But, there are many conditions that can trigger acute renal failure. These conditions are classified into three main categories: prerenal, intrarenal, and postrenal.
- Prerenal conditions are those that impede or interfere with the blood before it reaches the kidneys. They do not actually damage the kidneys, they just prevent them from doing their job by not allowing enough blood to reach the kidneys. Prerenal conditions are typically the most common causes of acute renal failure. The list includes:
- Extremely low blood pressure: This can occur due to excessive bleeding, shock, dehydration, major trauma, as a complication of major surgery, or from a blood infection called sepsis. With critically low blood pressure, the blood is not able to effectively reach the kidneys.
- Heart failure: If the heart is unable to pump a sufficient amount of blood, it cannot reach the kidneys to get filtered. Typical scenarios for this are a heart attack or congestive heart failure.
- Low blood volume: Certain situations can lower the quantity of blood in your body to the point where enough will not be available to reach the kidneys. Causes for this can include major burns, dehydration from excessive diarrhea or vomiting, or heatstroke.
- Intrarenal conditions affect the actual kidney organ itself, whether by hurting its structure, or its ability to function, or both. Common intrarenal conditions include:
- Ischemia: This disorder refers to a family of conditions that can damage the kidney by reducing the amount of blood supply to the organ. This lack of blood causes the tissues to malfunction and deteriorate.
- Atheroembolic kidney disease: This occurs when blood clots (emboli) travel to the kidneys and accumulate within the arterioles of the organ, causing inflammation and tissue damage. This commonly occurs during a cardiac catheterization, a diagnostic/treatment procedure done on heart patients.
- Hemolytic uremic syndrome: This is one of the most common causes of acute kidney failure in infants and children. It is caused by E. coli bacteria that has caused an intestinal infection. The infection produces a toxic substance that triggers swelling in the tiny blood vessels of the kidneys, and resulting damage to the organs.
- Postrenal conditions affect the flow of urine out of the body after it has left the kidneys and is on the way to the bladder. They usually occur in two forms:
- Ureter obstruction: The ureters are tubes that transport urine and run from the kidneys to the bladder. Kidney stones or tumors in the area are the most common causes of ureter obstruction. When urine backs up into the kidneys, damage and ultimate kidney failure can occur.
- Bladder obstruction: Blood clots, tumors, an enlarged prostate in men, bladder stones, or nerve dysfunction can result in bladder obstruction and resulting kidney damage.
Chronic Kidney Failure:
Most chronic kidney disease is caused by progressive illnesses that develop over time. The most common examples include:
- Diabetes: This common malady occurs when the body cannot produce or use insulin properly. Without insulin, we cannot break down glucose, and a serious medical condition can result. One of the side effects of diabetes is damage to tissues in the nephrons that are key to the filtering functions of the kidneys.
- Hypertension: High blood pressure is both a cause and symptom of chronic renal failure. Blood flowing through the kidneys at excessive pressures damages the organ progressively.
- Polycystic kidney disease is an inherited condition that results in the formation of cysts on the nephrons, eventually damaging the function of the kidneys.
- Obstructive nephropathy: This condition is caused by such things as prostate enlargement, kidney stones, or tumors that causes urine to flow backwards from the bladder back into the kidney. This “backpressure” can cause progressive damage to the organ.
- Exposure to toxins: Long-term, persistent exposure to chemicals such as lead, fossil fuels, and solvents can cause damage to the kidneys over the years, and eventually result in chronic kidney failure.
What Are the Symptoms of Kidney Failure?
Acute Renal Failure:
- Anemia: Kidney damage can result in lowered production of red blood cells
- Edema: Swelling in the face and extremities.
- Lower back pain
- Frequent urination
- Halitosis: Urea in the saliva can produce bad breath and an ammonia taste in the mouth.
- Foamy or bloody urine: Due to excessive protein in the urine.
- Itchy skin: Phosphorous build up in the blood.
- Stunted growth in children
Chronic Renal Failure:
- Unexplained weight loss
- Yellowish-brown skin
- Decreased alertness
- Muscle cramps and twitches
- Vague sense of unease
- Bloody, tarry stools (indicator of internal bleeding)
- Itchy skin
What Treatments Are Available for Kidney Failure?
The most effective treatment for both acute and chronic kidney failure is dialysis. The big difference is that dialysis for most acute cases can bring the kidneys back to normal in a matter of weeks. Dialysis in chronic cases, on the other hand, is a life-preserving measure that will go on as long as the patient lives, unless they were to receive a kidney transplant. There are three main types of dialysis available:
- Hemodialysis is the traditional form of dialysis that most people are aware of. Patients are hooked up to a dialysis machine for several hours at a time, usually about twice a week. Their blood is taken out or their body, and run through an artificial filtration system. Toxins are removed, some necessary substances that the kidney normally provides are added, and the purified blood is returned to the patient’s body.
- Hemofiltration is a continuous process that is usually used to treat acute renal failure in critically ill patients. This slower process is much easier for these very sick people to handle, and it can usually arrest the kidney failure if they survive the primary accompanying conditions. Other nutrients and medications can also be delivered intravenously while the dialysis is occurring.
- Peritoneal dialysis is a type of dialysis that is often used on children or otherwise healthy adults that have acute kidney failure. This procedure involves the use of the lining of the patient’s abdomen (peritoneum) as a filter for the blood in lieu of the kidneys. This is not a continuous process, but is done for appropriate amounts of time on a regular schedule based on the patient’s needs and condition.
The outlook for treating acute renal failure is much more rosy than for chronic. Most cases of acute can be turned around. In fact more people with acute renal failure die from the primary condition, than from the kidney failure. A certain amount of acute cases can develop irreversible kidney damage that will result in chronic renal failure, but these cases are the exception.
Chronic kidney failure will shorten the lives of its victims, and dialysis must continue for life. Kidney transplants are an option for some folks, but many patients are too sick to tolerate the donated organs. There is also an ongoing shortage of available donors.
The best thing we can do is take care of ourselves and pursue a healthy lifestyle that will give us the best chance for avoiding conditions such as kidney failure.