INTRODUCTION TO RENAL DISEASES
Humans possess two bean-shaped, dark-red colored kidneys. In adults, the kidneys measure 12cm each and weigh 130 to 170g each. They are located on the back, on both sides of the spinal column and are protected by the lower ribs.
Each day the kidneys filter approximately 1,200 to 2,000 liters of blood, which arrive through the renal arteries. Inside the kidneys, the arteries are divided into increasingly tiny vessels, until they form a meshwork of very tiny capillaries that constitute the glomerulus. Actually, the glomerulus acts as the true filter of the kidney, whereby the blood passes and is filtered, eliminating all the unwanted substances through the urine. Each kidney possess nearly one million glomeruli.
Urine is formed through the elimination of unnecessary water, mineral salts and other products that are not supposed to build up in our blood. The daily quantity of urine formed from 1,200 to 2,000 liters of blood that pass through the renal filter is of 1,2 to 1,5 liters. From the kidney the urine works its way outwards, being drained by the ureter into the bladder and out through the urethra. Daily, in addition to water, through the urine are also excreted sodium, calcium, phosphorus, urea, uric acid and innumerable other catabolic products from our bodies. The metabolic work takes advantage of the beneficial substances for the organism and refuses what is not supposed to be assimilated (catabolic product), sending to the kidney where this is then excreted.
What is the Use of Kidneys?
Among their many functions, the following may also be highlighted:
The kidneys are responsible for the elimination of toxic waste produced by our organism, such as urea and uric acid. It is their function to filter, clean or purify.
The kidneys control the volume of fluids and, therefore, any water excess in the body is eliminated through the urine, known as the diuretic effect. The kidneys exert control over the mineral salts in our body, excreting their excesses or saving them in needy situations.
From the control of the volume (fluids) and salts, they exert a large influence over the arterial and venous pressure of our organism. The kidneys produce and secrete hormones: erythropoietin, Vitamin D and renin. Erythropoietin interferes with the production of red blood cells and their lack may lead to a hard-to-treat anemia. Vitamin D (calcipherol) controls the intestinal absorption of calcium, and renin, together with aldosteron, controls the volume of fluids and arterial pressure of our organism.
How can you tell your kidney is ailing?
The kidney can be hit by an immunological, inflammatory, infectious, neoplasic, degenerative, congenital or hereditary disease.
First and foremost, the patient should observe the urine, its volume, color, smell and the way it is been eliminated (stream). The volume of the urine may be increased or decreased. Large daily volumes, 3 to 4 litters, occur in diabetes. The color may be clouded, whitish or bloody.
Burning, painful, urgent urination, or intermittent flow several times during the day or night. If there is any edema in the feet, hands or the eyes. When the kidney is inflamed, infected or increased, due to a tumor or obstruction, constant back or flank pain occurs.
When there are calculi (stones) the pain is acute, intense and colicky (spasm-like). The patient suffering from diabetis, gout, rheumatism and arterial hypertension is more prone to renal diseases.
Clinical examination may reveal a pale and dry skin, swollen leg and eyes, signs of anaemia, back pain on palpation or percussion and arterial hypertension.
A routine urine test may reveal albumin, glucose, blood, pus and bacteria; the blood test shows altered rates of urea, uric acid, creatinin, phosphorus, calcium, and other substances retained due to the difficulty in filtering.
An ecograph or X-ray may be necessary to view the presence of calculi, signs of obstruction of the urinary tract, alterations in kidney shape and size.
The main kidney diseases and their most comon characteristics:
Nephritis : is characterized by the presence of albumin and blood in the urine, edema and hypertension.
Urinary Infection: the patient complains of painful, burning and urgent urination. The amount of urine excreted becomes small and frequent, both during day and night. The urine is cloudy and foul-smelling, and blood may result in the final phase of urination. In cases where the infection hits the kidneys, fever, low back pain and chills appear, in addition to burning and urgency on urination.
Renal Calculi (kidney stones): Renal colic, with side and back pain, is very common, often with blood in the urine and, in some cases, and calculi elimination may occur.
Urinary Obstruction: occurs when there is a blockage of the passage of urine through the urinary ducts due to calculi, an enlarged protate, tumors, ureteral and urethral stenosis. The absence or small amount of urine is the characteristic complaint of urinary obstruction.
Acute Renal Failure: It is caused by a sudden offense to the kidneys, due to the lack of blood or pressure in the formation of urine, or the acute obstruction of the urinary tract. The main characteristic is the total or partial absence of urine.
Chronic Renal Failure: it occurs when the renal function is irreversibly deteriorated by the action of a certain disease over the kidneys causing, among others. urea retention, anaemia, and arterial hypertension.
Begnin and malign tumors may affect the kidneys. The complaints include palpable masses in the abdomen, pain, blood in the urine and urinary obstruction.
Multisystemic Diseases: the kidneys may be affected by rheumatic diseases, diabetes, gout, collagenosis and immunologic diseases. Urinary alterations in diseases such as nepfritis, generally with the presence of blood and albumin in the urine, may appear.
Congenital and Hereditary diseases: an example of these diseases is the growth of numerous cysts in the kidneys (polycystic kidney)
Toxic Nephropathies: it is caused by toxic agents, physical and chemical, and drugs. They are characterized by nephritic manifestations and functional kidney failure.
Questions You can Ask Your Doctor:
Swelling near the eyes or legs is always a sign of renal disease?
Are my kidneys ailing because I have been urinating blood?
Is urinary infection always from the kidneys?
I have a relative with a policystic kidney. Am I also prone to suffer from this disease due to the kinship?
Does Kidney failure affect both kidneys?
Can chronic renal failure treatment improve my kidneys?