Dr Rotimi Adesanya
What is a kidney stone?
A kidney stone also called renal calculi, nephrolithiasis or urolithiasis is a hard object that is made from chemicals in the urine. There are four types of kidney stones: calcium oxalate, uric acid, struvite, and cystine. Urine has various wastes dissolved in it. When there is too much waste in too little liquid, crystals begin to form.
The crystals attract other elements and join together to form a solid that will get larger unless it is passed out of the body with the urine. Usually, these chemicals are eliminated in the urine by the body’s master chemist: the kidney. In most people, having enough liquid washes them out or other chemicals in urine stop a stone from forming. After it is formed, the stone may stay in the kidney or travel down the urinary tract into the ureter. Sometimes, tiny stones move out of the body in the urine without causing too much pain. But stones that don’t move may cause a back-up of urine in the kidney, ureter, the bladder, or the urethra. This is what causes the pain.
Causes
Possible causes include drinking too little water, exercise (too much or too little), obesity, weight loss surgery, or eating food with too much salt or sugar. Infections and family history might be important in some people. Eating too much fructose correlates with increasing risk of developing a kidney stone.There are four main types of stones:
1. Calcium oxalate: The most common type of kidney stone which is created when calcium combines with oxalate in the urine. Inadequate calcium and fluid intake, as well other conditions, may contribute to their formation.
2. Uric acid: This is another common type of kidney stone. Foods such as organ meats and shellfish have high concentrations of a natural chemical compound known as purines. High purine intake leads to a higher production of monosodium urate, which, under the right conditions, may form stones in the kidneys. The formation of these types of stones tends to run in families.
3. Struvite: These stones are less common and are caused by infections in the upper urinary tract.
4. Cystine: These stones are rare and tend to run in families.
Symptoms
Some kidney stones are as small as a grain of sand. Others are as large as a pebble. A few are as large as a golf ball! As a general rule, the larger the stone, the more noticeable are the symptoms.The symptoms could be one or more of the following:
• severe pain on either side of your lower back
• more vague pain or stomach ache that doesn’t go away
• blood in the urine
• nausea or vomiting
• fever and chills
• urine that smells bad or looks cloudy.
Investigation
your doctor might ask you to have a urine test, blood test, x-ray and/or CT scan. A CT scan sometimes uses contrast dye. If you have ever had a problem with contrast dye, be sure to tell your doctor about it before you have your CT scan.
Investigation
The health of your kidneys will be evaluated by blood tests and urine tests. Diagnosis of a kidney stone starts with a medical history, physical examination, and imaging tests. This can be done with a high resolution CT scan from the kidneys down to the bladder or an x-ray called a which will show the size of the stone and its position. The KUB x-ray is often obtained by the surgeons to determine if the stone is suitable for shock wave treatment. The KUB test may be used to monitor your stone before and after treatment, but the CT scan is usually preferred for diagnosis. In some people, doctors will also order an intravenous pyelogram or lVP.
Treatment
The treatment for kidney stones is similar in children and adults. You may be asked to drink a lot of water. Doctors try to let the stone pass without surgery. You may also get medication to help make your urine less acid. But if it is too large, or if it blocks the flow of urine, or if there is a sign of infection, it is removed with surgery.
Shock-wave lithotripsy is a noninvasive procedure that uses high-energy sound waves to blast the stones into fragments that are then more easily passed out in the urine. In ureteroscopy, an endoscope is inserted through the ureter to retrieve or obliterate the stone. Rarely, for very large or complicated stones, doctors will use percutaneous nephrolithotomy/ nephrolithotripsy
Complications
Kidney stones increase the risk of developing chronic kidney disease. lf you have had one stone, you are at increased risk of having another stone. Those who have developed one stone are at approximately 50% risk for developing another within 5 to 7 years.
