The kidneys send this residue to the bladder in the form of urine. 
The body removes the toxins in the urine during urination.
Renal failure (RI) occurs when the kidneys lose the ability to adequately filter blood.
If the kidneys can not work, the body gets overwhelmed with toxins. 
Without treatment, this disease can be deadly.

Chronic kidney failure develops in a few months or years.

Classification of renal failure

Acute renal failure Acute
renal failure is the rapid loss of renal function.

Chronic Kidney Failure
When the kidneys do not work well for at least 3 months, kidney failure is chronic.
Regardless of the cause, this disease progresses to uremic syndrome.


Types of acute renal failure

Acute renal or functional impairment Pre-renal
acute renal failure is a sudden loss of renal function due to a reduced supply of blood to the kidneys.
There are no problems with the filtering capacity of the kidneys.
It is the most frequent form, occurs in case of decrease of circulating blood volume and vasoconstriction.
Precisely for this reason, numerous drugs, such as ACE inhibitors, beta-blockers, NSAIDs and iodinated contrast agents, can induce acute renal failure in a dehydrated individual.
If blood supply is very low, ischemia (interruption of blood flow) may occur with acute tubular necrosis (death of tubular cells).

Acute or Intrinsic
Renal Failure Intrinsic acute renal failure is a sudden loss of kidney function caused by internal kidney damage.
Ninety percent of cases of this form of acute renal failure are caused by toxins, or by an insufficient amount of oxygen available in the kidneys (ischemia).
In acute pre-renal renal failure, the damage is caused by reduced blood flow in the kidneys, while in this case there is an organic damage at the level of:

  1. glomerulosa,
  2. Tubules,
  3. Interstitial

Acute obstructive or post-renal
obstruction A partial obstruction of the urinary flow causes increased pressure in the damaged kidneys, usually bilateral.
It is the rarest form of acute renal failure (5% of cases) due to mechanical obstruction of the renal pelvis, ureters, bladder or urethra.
When only one kidney is affected, laboratory tests are negative (normal creatinine).
Since each kidney is sufficient to eliminate waste , obstruction of a ureter causes acute renal failure in patients:

  1. With only one kidney,
  2. With severe chronic kidney disease.

Bilateral obstruction is usually caused by prostate cancer in men and gynecological neoplasms in women.

Among the causes are:

  1. Increased prostate ,
  2. Stones in the kidneys ,
  3. Stones in the bladder,
  4. Neurogenic bladder.


Causes of acute renal failure

Acute renal failure may occur when:

  1. A disease decreases the flow of blood to the kidneys,
  2. Some damage occurs within the kidneys,
  3. The urinary tract is blocked and waste can not be expelled through the urine.

Altered blood flow to the kidneys
Among the diseases, conditions, and medications that can reduce blood flow to the kidneys are:

  1. Loss of blood or fluid
  2. Heart attack
  3. Heart disease
  4. Infection
  5. Hepatic insufficiency
  6. Use of aspirin, ibuprofen (brufen), naproxen sodium (Aleve) or related medications
  7. Medications for blood pressure
  8. Severe allergic reaction (anaphylaxis)
  9. Severe burns
  10. Severe dehydration

Kidney damage
Some diseases, conditions and substances can damage the kidneys and cause acute renal failure:

  1. Blood clots in the veins and arteries of the kidneys;
  2. Cholesterol plaques that block blood flow in the kidneys;
  3. Glomerulonephritis , inflammation of small filters in the kidneys (glomeruli);
  4. Hemolytic-uremic syndrome , a disease resulting from the premature destruction of red blood cells;
  5. Infection;
  6. Lupus , a disorder of the immune system that causes glomerulonephritis;
  7. Drugs – for example, chemotherapeutics, antibiotics and radiological contrast agents;
  8. Scleroderma , a rare disease that affects the skin and connective tissues;
  9. Thrombotic thrombocytopenic purpura , a rare blood disease;
  10. Toxins such as alcohol and heavy metals;
  11. Muscle tissue rupture (rhabdomyolysis) leading to kidney damage caused by accumulated toxins during the destruction of muscle tissue;
  12. Tumor lysis syndrome , the disruption of cells from a tumor causes the release of toxins that can cause injury.

Urine Blocking in the Kidneys
Diseases that block the passage of urine are:


Symptoms of acute renal failure

Among the symptoms of acute renal failure are:


Renal insufficiency in the elderly

Old age is one of the risk factors for kidney disease due to anatomical and functional changes related to age in the kidneys.
With increasing age, the number of nephrons (functional units of the kidney) decreases and this reduces kidney function.

However, in the elderly the most frequent reason for renal failure is the narrowing of the renal arteries due to the deposition of fat in the walls of the artery.
Symptoms include:

  • Immune system dysfunction;
  • Decreased ability to concentrate;
  • Memory deficit;
  • Decreased attention;
  • Delirium;
  • Reduced verbal fluency.


Complications of renal failure

Consequences of renal insufficiency in blood potassium levels
Hyperkalemia (excess potassium) caused by the reduction of K + (positive potassium ions) clearance in the kidney may occur in acute and chronic renal failure.
The kidney does not work properly in people with kidney disease.
Usually, they are not able to properly regulate the level of potassium. This can cause an excess of potassium in the blood.
Even some medications used to treat kidney disease can increase potassium and make it worse.

Potassium usually increases slowly for weeks or months. The consequence is fatigue or nausea .
If potassium suddenly increases, the patient may have:

  1. Difficulty breathing ,
  2. Chest pain ,
  3. Heart palpitations.

This is a very serious health problem.

Hyperparathyroidism caused by renal failure
This is a problem caused by chronic kidney disease linked to changes in calcium-phosphorus metabolism.
The diseased kidney does not produce vitamin D3 that serves to absorb calcium in the intestine.
The consequence is the reduction of calcium in the blood.
In addition, the diseased kidney can not suppress phosphorus, so it increases the level of this mineral in the blood.

The parathyroid glands are four small glands that produce PTH (parathyroid hormone) and collaborate in the regulation of calcium-phosphorus metabolism.
In case of renal failure, the production of PTH increases because:
This hormone:

  • Reduces phosphorus in blood,
  • It takes calcium from the bone to raise the level of calcium in the blood.

The consequence of chronic secondary hyperparathyroidism is the reduction of calcium density in the bones ( osteoporosis ).
If the level of phosphorus is high and calcium returns to normal (the product of calcium (Ca) x phosphorus (P) is greater than 65-70 mg / dl) causes the accumulation of calcium phosphate in the tissues of the human body, for example:

  1. At the lung level, where they can cause gas diffusion problems
  2. In the blood vessels, the formation of calcifications occurs , soon atherosclerosis accelerates, particularly in the coronary arteries.


Causes of death in patients with acute renal failure

Sepsis (systemic infection) 29%
Gastrointestinal bleeding 24%
Cardiac 9%
Sangramento + Because 6%
Respiratory insufficiency 6%
Others 26%


Diagnosis of renal failure

Renal insufficiency can be confirmed by instrumental exams and laboratory tests (blood and urine).
The doctor should check the patient’s medical history, in particular, it is important to know if this is the first time the exams have been changed.
You should also check for FG (one of the most important values ​​for diagnosis).

Urine tests IR
Intrinsic IR
Sodium in urine
(Mmol / L)
< 10 > 20-40
Osmolality of urine
(MOsm / L)
> 500 < 350
Urea in urine /
Plasma urea
> 8 < 3
Creatinine in Urine /
Plasma Creatinine
> 40 < 20
sodium excretion (%)
< 1 > 1

Urine concentration helps in the diagnosis, in case of insufficiency:

  1. Renal pre-renal, the patient reabsorbs water and sodium, soon the urine is concentrated;
  2. Intrinsic, the kidney can not concentrate the urine.


Laboratory analysis

Blood urea nitrogen and creatinine levels in the blood are indicators of renal health;
The creatinine reference values ​​are:

  • Adult males: 0.8-1.3 mg / dl
  • Adult women: 0.6-1.1 mg / dl

To assess the functionality of the kidney, azotemia and creatinine clearance are also required.
Normal values ​​of:

  • Azotemia: 8-20 mg / dl
  • Creatinine clearance: 60-130 ml / min

Formula to calculate creatinine clearance (Cockcroft and Gault)

  • Males: (140 – age) x weight / (creatinine x 72)
  • Females: male formula x 0.85

Other useful blood tests are:

  • Blood count
  • pCR
  • Protein profile
  • Sodium, potassium, chlorine, calcium and phosphorus,
  • Blood gas analysis

Urine tests
For diagnosis, your doctor needs this information:

  • Specific weight : in pre-renal insufficiency is greater than 1020, in organic renal failure has a value between 1010 and 1012 because the kidney loses the ability to concentrate urine;
  • Sediment : presence of red blood cells, white blood cells or hyaline cylinders,
  • Proteinuria ,
  • Culture of urine,
  • Urine volume;


Exams and Tests

  1. After checking blood and urine, renal ultrasonography is the first test to be performed to understand the type of kidney failure.
    This test shows if the disease is caused by an obstruction.
    Abdominal ultrasound is also used to check for reduced kidney size;
  2. The CT or MRI are recommended for detecting an abnormal mass or obstruction;
  3. Chest X-ray to exclude lung infections, since they are very common in the elderly and sepsis can be a cause of pre-renal renal failure.
  4. ECG showing whether potassium caused problems


Treatment for renal failure

The disease is cured by the nephrologist.

Treatment for acute renal failure depends on the type.
The 4 pillars of therapy are the correction of:

  1. circulating blood olume – infusions of isotonic solution / furosemide use (diuretic) to maintain diuresis,
  2. Acidosis with the injection of bicarbonates, although often not useful,
  3. Hyperkalemia  – very important,
  4. Blood abnormalities , for example anemia, but in reality are not very used.

In any case, consultation with a nephrologist is recommended as soon as possible.

Upon arrival in the emergency room, the ACE inhibitor and metformin should be discontinued. Many patients take this medicine for diabetes , but it is contraindicated in cases of kidney failure because it overloads the kidneys, so the buildup can cause lactic acidosis.

If the patient is dehydrated , intravenous fluids are given to replace fluid loss and hydrate the body.

Patients who have accumulated a large amount of fluid in the body should take diuretic medications to eliminate excess fluid.
In addition, these patients should limit the intake of fluids that must be proportional to the production of urine.

Drugs for controlling blood potassium
If the kidneys do not adequately filter potassium, your doctor may prescribe calcium, glucose, or sodium polystyrene sulfonate.
Too much potassium in your blood can cause:

Due to the decrease in calcium levels , some patients need to infuse this mineral.

Along with medications, proper nutrition for kidney failure is also important in minimizing the accumulation of toxins.
Patients are often advised to diet low in protein and salt.

Patients with renal impairment should avoid or reduce their intake of certain medicines such as Allopurinol (Zyloric ®) and azithromycin (Zitromax ®), Valacyclovir (VALTREX ®) and heparin.


Recommended diet for kidney failure

There are no natural remedies for kidney failure, but diet can reduce kidney overload.
Excessive consumption of high protein foods helps some kidney disease. So your doctor recommends limiting your protein intake.
Foods like meat, eggs and dairy products should be avoided as much as possible when you follow the ideal diet for kidney failure. It is also advisable to limit the consumption of vegetables rich in proteins.
According to conventional medicine, foods rich in complex carbohydrates like grains and whole foods are safe for health.

However, according to natural medicine and in particular with the blood type diet (a diet usually effective to treat many diseases), cereals are usually the cause of kidney failure.
In particular, gluten-containing cereals are the most harmful.
In fact, these foods harm the kidney and do not allow adequate blood filtration.

So, based on this type of natural medicine, the problem is not excess protein, but kidney filter screens that are too large and allow protein to escape.
In addition, the immune system may not be compatible with certain blood-based foods, for example, people in group B generally do not tolerate tomato.

Since renal failure causes the deposition of salts and toxins inside the body, it is necessary to reduce the intake of these substances.
You should prepare low-sodium recipes , otherwise you run the risk of water retention in the body.
Foods rich in potassium and phosphorus (cheese, baking powder, meat, almonds, etc.) should be eaten in small amounts.


Is kidney damage reversible? Does kidney failure have a cure?

The answer to this question depends on the stage of kidney failure.
Decreased renal function is reversible.

Removal of the obstruction that causes acute renal failure, treatment of diabetes and blood pressure may partially reverse damage to the kidneys.
These methods help prevent the worsening of the kidneys that would cause death.
The last stage of renal failure is uremia, that is, the accumulation of urea and nitrogenous substances in the blood.

Read too