RENAL CALCULI

What are Renal Calculi ?

• Urine passes away from the kidneys, down a tube on each side called the ureter, and into the bladder. From here, the urine is discharged through the urethra

• If there is too much of certain waste products in the urine, these substances form crystals

• Crystals can then combine to form stones.

• The stones may lie in the kidney, and often do not cause symptoms there.

• However, when they pass down the ureter on their way to the bladder, pain usually occurs

• If a stone gets stuck on its way down the ureter, pain usually occurs in the form of renal colic.

• This is a griping pain which can be very severe.

• Blood may be passed as well, due to the irritation of the lining of the ureter by the sharp-edged stone.

• As the stone is being passed, the pain may be felt in the penis (males) or in the vaginal area (in females).

•Once the stone has passed, the bleeding and pain stop quite abruptly.

Symptoms

• Sudden severe and excruciating back pain which may come and go and often radiates from the back across the abdomen and into the genital area or inner thighs

• may be associated with nausea, vomiting, abdominal bloating, possible blood in urine, pain during urination and chills and fever.

• Stones in the urinary tract can be one of the most painful conditions known to humankind.

How do Renal Calculi occur ?

• Very concentrated urine

• Hot climates

• Increase in the concentration of certain waste product.

Types of calculi

1. Calcium stones occur when there is too much calcium in the urine.

This may happen if there is too much calcium in the diet from milk, cheese or bread.

Some people seem to absorb more calcium from the gut and there is nowhere for it to go other than into the urine.

Other people may have an overactive parathyroid gland (hyperparathyroidism). This results in calcium being leached out of the bones and again it has nowhere else to go but the urine.

2. Oxalate stones can occur if there is too much oxalate in the diet (e.g spinach, chocolates and certain nuts).

They are more likely to occur in people who have a bowel problem in which fat is not being absorbed properly.

3. Uric acid stones form when there is too much uric acid in the urine.

This comes as a direct result of too much uric acid in the blood.

This is particularly likely in people who are prone to the condition of gout.

High concentration of uric acid usually occurs in people who consume food rich in proteins.

4. Cystine stones are an uncommon problem where the kidneys leak high quantities of the amino acid cystine.

Why do Renal Calculi occur ?

• Inherited tendency

• Infections

• Low urine flow.

• Kidney stones form when a change occurs in the normal balance of water, salts, minerals, and other things found in urine.

• The most common cause of kidney stones is not drinking enough water.

Tests to diagnose kidney stones

• CT scan (spiral computed tomography ) of the

ureters and kidneys, but the scanner moves in a circle as you move through the machine.

• Intravenous pyelogram (IVP) The doctor injects a special dye into

the patient. A technician will then take x-rays as the dye enters the kidneys and travels down the urinary tract.

Spiral CT scan

Urine Tests

• Urine samples are required to evaluate features of the urine, including its acidity and the presence of:

• Red or white blood cells

• Infection

• Crystals

• High or low levels of chemicals that inhibit or promote stone formation

Microscopic Examination

• The kidney stones obtained from the urine sample are examined under a microscope.

• The crystal formations are often specific enough so that the doctor is able to identify the substance causing the stone.

Testing the Acidity of Urine

• Testing whether urine is acidic or alkaline helps to identify the specific type of stone:

• A pH value of 7.0 is neutral.• A solution with a low pH (below 7.0) is

acidic. (A low pH favors uric acid and cystine stones.)

• A solution with a high pH is alkaline. (A high pH favors calcium phosphate stones.)

Testing for Blood in the Urine

• AA dipstick test for blood in the urine (called hematuria) is typically performed when patients appear in the emergency room with flank pain (the primary symptom of kidney stones).

• About a third of kidney stone patients, however, do not show blood in the urine, so other tests may be needed.

Blood Tests

• Blood Tests for Stone Factors

• Parathyroid Tests

• Tests for Infection

• Tests for Metabolic Problems