Q: I went to the ER over a week ago and was told I had a kidney stone. The pain was unbelievable. The doctors said that I would pass the stone but I haven’t yet. Is this cause for concern? How soon should a kidney stone pass?
A: Kidney stones often pass within hours to days after the onset of symptoms, but there's no specific time schedule. The passage often depends on the size of the kidney stone and its ability to move, especially after drinking an increased amount of water. In the meantime, the key is to control the pain and watch for any potential complications such as fever or difficulty with urination. If you've had this pain for more than a week, the stone may be stuck due to its size, shape or current location. It's also possible you've already passed the kidney stone without realizing it.
The emergency physician’s job is to provide medical care for an urgent health problem at a specific point in time. When you're discharged, it's important that you schedule a follow-up visit with your primary-care physician. This is key because it helps to ensure that any continuing health care needs, such as attending to the pain you experienced from your kidney stone, will be addressed.
Causes of kidney stones
Many factors may contribute to the formation of kidney stones, but, in general, they are the result of a super concentration of urinary chemicals that form crystals on the inner surfaces of the kidneys. Over time, they may combine to form small, hard and stone-like masses that can travel from the kidney and into the ureter(s), bladder or urethra.
While most kidney stones contain calcium, others may contain crystals that include uric acid (more likely if you have gout or eat a high-protein diet), struvite (found more often in women and related to urinary tract infections) or cystine (due to a hereditary disorder).
Both men and women are at risk, but kidney stones are more likely to occur in men between the ages of 40 to 70, as well as in those individuals who have had a personal or family history of these type of stones. Other factors that may contribute to the formation of kidney stones include the following:
- Inadequate fluid intake
- Frequent kidney infections
- High-protein and high-salt diets
- Inactivity (which causes the bones to release more calcium into the blood)
- Obesity
- Medical conditions such as gout, hypercalciuria (high calcium in the urine), hyperparathyroidism, kidney disease, uncontrolled high blood pressure and diabetes
- Inflammatory bowel disease, gastric bypass surgery or other disorders of the digestive system that may affect the absorption of calcium
- Medications such as diuretics or high doses of calcium containing antacids
- Geographic location (individuals who live in hot and dry areas are at a higher risk for dehydration, and, in turn, kidney stones)
Symptoms
Many people are unaware they have stones because they may linger in the kidneys or pass through the urinary tract without causing any symptoms. However, other individuals may feel a dull ache or even a sudden burst of pain that fluctuates in intensity. Other symptoms may include the following:
- Pain lasting minutes to hours with intervals of relief
- Pain in the small of the back, under the ribs, and/or in the lower abdomen that may move downward and into the groin
- Blood in the urine
- Nausea and vomiting
Some people may also have an accompanying urinary tract infection with symptoms that may include the following:
- Pain or a burning sensation with urination
- Frequent urge to urinate
- Cloudy or foul-smelling urine
- Fever, chills and body weakness
The diagnosis
Sometimes, "silent" kidney stones are discovered after an individual receives a rib or abdominal X-ray for another health condition. Tests like ultrasounds or X-rays for pain or blood in the urine (hematuria) may also reveal kidney stones.
Once kidney stones are found, a radiographic procedure known as an intravenous pyelogram (IVP) or computerized tomography (CT) scan may be recommended. Blood tests for uric acid and calcium, as well as a urine test to check for an underlying urinary tract infection, may be needed.
Treatment of kidney stones
Treatment of kidney stones depends on the symptoms and their potential complications, such as a blockage of the urinary flow in the ureters, bladder or urethra, and/or unrelenting pain. Fortunately, most small stones pass through the urinary tract by themselves and without medical intervention. To help this process, your doctor may recommend drinking two to three quarts of water per day, depending upon your current state of health and hydration status. If the stone becomes stuck or is too large to pass, medical intervention will be needed. Options include the following:
- Extracorporeal shock wave lithotripsy (ESWL) uses shock waves to vibrate the stone to such an extent that it shatters and breaks into smaller particles.
- Medications can be used to help prevent the formation of stones due to conditions such as hypercalciuria and/or high levels of uric acid.
- Uteroscopic stone removal uses a small instrument that is passed through the bladder and into the ureter to remove a stone stuck in that region of the urinary tract.
- Percutaneous nephrolithotomy (tunnel surgery) is the surgical removal of stones located inside the kidney(s).
- Surgical removal of the parathyroid glands can be done if they are overactive and produce high levels of calcium and calcium containing kidney stones.
Prevention
While no one measure can prevent the formation of a kidney stone, a combination of the following may decrease their occurrence.
- Water intake. The amount you need to drink varies and depends upon factors such as your level of activity, perspiration rate, climate and health conditions that may impact your overall body fluid balance. This is best discussed with your personal physician.
- Dietary changes, especially if you tend to form calcium oxalate stones. Limit foods high in oxalates such as sweet potatoes, almonds, soy and soy products, refried beans and spinach. For up-to-date information, visit the American Dietetic Association.
- Lemonade made with real lemons. According to MayoClinic.com, one glass per day will “increase the levels of citrate in your urine, and citrate helps prevent stone formation.”
- Regular visits with your doctor to review medications, medical conditions and treatment options if you tend to have repeat episodes of kidney stones.
For further information, please visit the United States National Library of Medicine and the National Institutes of Health as well as the National Kidney and Urologic Diseases Information Clearinghouse.
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