Function of Kidneys and Diseases

Kidneys are filtered organs present in vertebrates which help in removing water-soluble wastes from the blood. A normal human body possesses two kidneys which are bean-shaped and weigh around 150 g

Kidneys are filtered organs present in vertebrates which help in removing water-soluble wastes from the blood. A normal human body possesses two kidneys which are bean-shaped and weigh around 150 grams each.

Kidneys function as the waste disposal system of our body. Every day kidneys are processing around 200 liters of filtrate while absorbing a large amount of it and producing around 1 to 2 liters of wastes.

Kidneys allow re-absorption of molecules from this filtrate into the blood. Thereafter these molecules are transferred to the urinary bladder and then expelled from the body as urine. Kidneys also produce hormones like erythropoietin, vitamin D, and enzyme renin.

Kidneys perform homeostatic functions which include regulating acid-base balance, blood pressure, electrolyte balance and extracellular fluid volume. The waste products include nitrogenous wastes urea and uric acid.

Main kidney problems

Kidney problems are divided into two groups:

Medical diseases:

These include:

• Urinary tract infection
• Kidney failure (Renal failure) and
• Nephrotic syndrome

These problems are treated by nephrologists.

Surgical diseases:

Surgical diseases include:

• Kidney stone,
• Prostate problems and
• Cancer of urinary system

These diseases are treated by urologists with surgery, endoscopy, and lithotripsy.

Common Causes of Kidney Disease

In kidney diseases, the nephrons are attacked due to which the capacity to remove wastes from the blood. The different causes of kidney diseases are:

• Diabetes
• High Blood pressure
• Genetic problems
• Injuries
• Overuse of painkillers
• Consumption of illegal drugs

Kidney Failure(Renal failure or renal insufficiency): It is a medical condition in which kidneys are unable to function properly. There are numerous causes of kidney failure out of which some cause is treatable and can bring back the kidney to a normal state.

But in some cases, the failure can be advanced and reversible. People suffering from kidney failure experience nausea, weakness, hunger loss. Blood and urine tests are done for diagnosis. There are two types of renal failure which are categorized by the trend in the serum creatinine.

Other factors include anemia and kidney size on sonography. In chronic kidney disease, the kidney size reduces and the patient suffers from anemia.

Kidney failure is of two types:

Acute Kidney Injury:

In acute kidney injury (AKI) there is an abrupt progressive failure in the kidney filtration process but it is not very common. It was known as acute renal failure (ARF) previously. It is mostly characterized by oliguria (decreased urine production and imbalance in fluid and electrolyte concentration).

There are various causes for AKI which are classified as prerenal, intrinsic, and postrenal. Proper identification of the cause must be done for the treatment and sometimes dialysis is done for a cure.

The causes for AKI can be:

• Painful injury with loss of considerable amount of blood
• Sepsis, a severe infection that can damage the kidneys
• Abrupt reduction in the blood flow to the kidneys due to low blood pressure
• Blood-clotting illness
• Urinary tract infections
• Enlarged prostate which can cause obstruction in the urine flow
• Certain toxins or drugs which are harmful to the kidneys
• Complications during pregnancy such as eclampsia and pre-eclampsia
• Sudden muscle breakdown releases myoglobin which is a chemical causing kidney failure. It often occurs in athletes who drink very less amount of fluids while participating in high endurance events
• Acute tubular necrosis
• Autoimmune kidney disorders

Diagnosis can be done by Kidney function studies, Peripheral smear, Complete blood count, Serologic tests, Fractional excretion of sodium and urea and by checking Bladder pressure. Renal ultrasonography is done for evaluating renal disease and blockage of the urinary system.

Aortorenal angiography also helps in the diagnosis of many renal vascular diseases. Renal biopsy is useful for identification of intrarenal causes of AKI.

Chronic kidney disease:

In most of the cases, kidney function starts worsening over a number of years which is actually good as it can help for early detection and further medication. Moreover dietary and lifestyle changes can improve the functioning of kidneys.

Chronic kidney disease (CKD) or chronic renal disease (CRD) occurs due to a progressive and gradual loss of renal function. Symptoms are not specific and might include loss of appetite and general illness.

The most common causes of CKD are

• Diabetes mellitus
• Hypertension or high blood pressure
• Glomerulonephritis, a group of diseases causing inflammation and damage to the kidneys
• Inherited diseases like polycystic kidney disease
• Malformations during pregnancy
• Lupus and other such diseases affecting the body’s immune system
• Kidney stones or an enlarged prostate gland in men
• Recurrent urinary infections

Symptoms of kidney failure include:

• Vomiting
• Weight loss
• Nightly urination
• Vomiting and/or diarrhea leading to dehydration which occurs due to a high percentage of urea in the blood.
• More frequent urination.
• Increase in the quantity of urine and often pale colored
• Less frequent urination with dark colored urine
• Blood in the urine
• Pressure or difficulty urinating
• Itching
• Muscle cramps
• Foamy or bubbly urine
• Difficulty in sleeping
• Tiredness
• Dizziness
• Difficulty in concentrating
• Darkening of the skin
• Muscle paralysis
• Swelling in the feet, legs, abdomen, ankles, face, and hands (often caused due to failure of kidneys to remove excess fluid)
• Shortness of breath (due to anemia)
• Pain in the back or side (due to fluid-filled cysts on the kidneys and sometimes in the liver)
• Low blood pressure
• Appetite loss and bad taste in the mouth
• Excess protein in the blood

Diagnosis of CKD is done using abdominal ultrasound for measuring the size of the kidneys. People suffering from CKD have kidneys size usually smaller (< 9 cm) than normal kidneys except in diabetic nephropathy and polycystic kidney disease.

Many times CKD is diagnosed during the screening of people who have diabetes, high blood pressure or who are in blood relationship with a person with chronic kidney disease. It is also recognized when a person suffers from heart disease, anemia or pericarditis.

Chronic kidney disease is diagnosed by a blood test for creatinine. If creatinine levels are high then it shows lower glomerular filtration rate which results in reduced ability of the kidneys in excreting waste products from the blood.

If creatinine levels are normal in the initial stages of CKD, then urinalysis (testing of a urine sample) is done which can show whether kidney is preventing the loss of protein or red blood cells into the urine or not. Medical imaging, blood tests and renal biopsy (a small sample of kidney tissue is removed) are other forms of tests which are used to find out the cause for the CKD.

How to know kidneys are functioning well or not:

To test the functioning of your kidneys you may undergo following tests:

• Blood pressure reading
• Blood test done for another reason.
• Urine test

If the doctor finds something wrong with the kidneys they may prescribe more tests such as x-rays, ultrasound pictures or a kidney biopsy. These tests are done to find out the precise damage to your kidneys.

GFR or Glomerular Filtration Rate is a measure of how well your kidney works. It also determines the stage of your kidney disease. Your doctor can easily calculate it from the results obtained through your blood test.

Facts needed:

• Ageas GFR reduces with age so age plays an important role.
• Sex, since most men have more muscle mass and GFR depends upon the muscle mass.
• Race, as African-Americans have more muscle mass as compared to other races, so it is important to know your race.
• Creatinine level which is a blood test result

When dialysis is preferable:

If kidneys fail completely to remove enough wastes from the blood then a person needs to go for dialysis. It usually occurs when only 10 to 15 percent of kidney function is left. The person has symptoms like swelling, vomiting, fatigue, and nausea. Sometimes these symptoms are not visible but the patient has a high amount of wastes in his/her blood which can be toxic.

Dialysis /hemodialysis

Dialysis is used to carry out some of the functions of kidneys when your kidneys fail. Two types of dialysis, hemodialysis and peritoneal dialysis are done.Hemodialysis (also hemodialysis) is used for removal of urea, creatinine and free water from your blood in a state of renal failure.

A dialysis machine and a special filter (called an artificial kidney or a dialyzer) are used to clean your blood in Hemodialysis. A minor surgery is done to get your blood into the dialyzer.

Kidney problems and regions:

As per study kidney problems are more in metros due to a high rate of obesity and fast food consumption among people.

How to protect our kidneys in safe:

• Avoid coffee, chocolate, sweets, and alcohols.
• Too many cold foods and iced drinks can harm kidneys.
• Prefer fresh fruit juice over stored ones except for unsweetened cranberry juice, which is good for the kidneys.
• Drink 10 glasses of water every day. Fluids in the form of soup and herbal tea can be taken.
• Increase sea salt and oil intake in winters.
• Consume seafoods, sea salt, fish more
• Get plenty of sleep.
• Overeating or eating late night can harm kidneys.
• Use meditation effectively

Latest treatments for kidney disorders:

• Micro-Chinese Medicine Osmotherapy,
• Immunotherapy (based on western medicines and Chinese medicines)

These treatments are commonly used in the clinic for patients with kidney disease around the world. They help patients to live a normal life without undergoing dialysis and kidney transplant.

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