About the Condition
Symptoms and Detection
The function of the kidneys is to filter waste chemical compounds from the body into the urine. Under certain conditions, the chemicals in the urine may form crystals, which combine to form urinary stones.
Urinary stones may block the flow of urine and cause severe pain, infection and affect the function of the kidney. Urinary stones are usually found either in the kidney, the ureters (tubes that direct urine from the kidneys to the bladder) or in the bladder and the urethra.
Not all persons with urinary stones will have symptoms. The symptoms, if present, include:
Screening and Testing
- colicky pain in the flanks, lower abdomen or radiating to the groin
- blood in the urine
- recurrent urinary tract infections
Urinary stones are detected using the following tests:-
1. Urine test
A urine test is carried out to determine if you are excreting too much minerals that contribute to urinary stone formation or too little inhibiting compounds.
2. X-ray of the kidneys, ureters and bladder
X-rays are taken of the urinary system and are checked for the presence of urinary stones.
This uses sound waves and high frequency radio waves to create images of organs in the urinary system and allows the doctor to check for the presence of urinary stones.
Abdominal CT scan
An abdominal CT scan is performed to locate urinary stones that do not show up on normal X-rays. You will need to fast for 4 to 6 hours before the test. A contrast dye is injected and a series of X-rays taken as the dye travels through the urinary system.
Risk Factors and Causes
The most common cause of urinary stones is low intake of water. The urine becomes concentrated and this allows chemicals to crystallize, thus setting the stage for urinary stone formation.
Other risk factors include:
- history of urinary stones or urinary tract infection
- family history of urinary stones
- high intake of calcium-rich foods (e.g. dairy products) or oxalate-rich foods (e.g. chocolates, peanuts)
You can prevent urinary stones from recurring by drinking lots of water, ensuring that you follow the prescribed medication or diet and having your condition monitored regularly.
The choice of treatment would depend on the size and type of urinary stone. Most urinary stones, if of small size, do not require treatment and may pass out in the urine eventually. Oral analgesics may be prescribed for pain management during passage of the stones. If treatment is required, the options include:-
Medication is prescribed to help ‘dissolve’ the urinary stones. This can only be used for specific types of urinary stones.
2. Extracorporeal Shock Wave Lithotripsy (ESWL)
This is a non-invasive procedure where shock waves are sent into the body to break the urinary stones into fragments. The fragments will pass out in the urine over the next few days.ESWL is indicated in cases with kidney stones (below 15 mm in diameter) and upper ureteral stones (below 10 mm in diameter). Patient can go home 2 – 3 hours after the procedure.
3. Percutaneous Nephrolithotripsy (PCNL)
This is a minimally invasive surgery where a small hole is made in the body to allow a scope to pass into the kidney. The urinary stone is broken up and removed through this tract. PCNL is indicated in cases of kidney stones with diameter above 15 mm.
4. Uretero-Renoscopy (URS)
This involves surgery where a small scope is passed through the urethra and bladder into the ureters and kidneys. The urinary stone is then broken up with laser and removed.
5. Laparoscopic removal
This is a minimally invasive surgery where 3 small holes is made in the body to allow a scope and some small instruments to approach the kidney and ureter. The urinary is opened and the stone is removed through this opening. This procedure is indicated for patients with ureteral stones with diameter above 15 – 20 mm