Why Do More People Get Kidney Stones in the Summer?
Summer is officially ‘kidney stone season.’ Understand why kidney stones are more common when the weather heats up.
Summer may have just officially started, but kidney stone season began a couple of weeks ago. Many doctors see an increase in kidney stone cases when the weather warms up.
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Kidney stones are solid, often sharp substances made of mineral and acid salts. They can travel into the ureter, which is the tube connecting the kidney and bladder, and cause excruciating lower back pain and genital discomfort.
Kidney stones also crop up more often in southern parts of the country and in regions close to the equator, says the National Institutes of Health (NIH).
“When patients come to the emergency room with pain, which is usually a sign that the stone is moving, it happens more often in the summer than in the winter months,” says urologist Manoj Monga, MD.
Dr. Monga has studied urine samples taken in the winter and the summer. He found that the risk of developing kidney stones is higher in the winter because there is typically more calcium in the urine during winter months. Having too much calcium in the urine, or hypercalciuria, is a risk factor for kidney stones.
Physical activity protects against stone development. So if you’re less active in the winter, your risk for developing a kidney stone increases. Then when warm weather hits, the stones that formed over winter start to move, Dr. Monga says.
“With activity, that stone starts to move and that’s when we find out that the stone is actually there,” he says.
More than 3 million patients – or nearly one person in eight – will see a primary care physician or urologist annually for kidney stones, according to the National Institute of Diabetes and Digestive and Kidney Diseases. Another half million will visit a local emergency room seeking relief. Kidney stones strike more men than women.
Kidney stones cause pain when the ureter contracts in an attempt to pull the stone through the bladder tube. If the surface of the stone is sharp or pointed, as it often is, the stone creates a nagging or stabbing discomfort in the lower back and/or groin, the NIH says.
Kidney stones vary in size — from as small as a grain of sand to as large as a pea. The smaller the stone, the more likely it can pass through the body without medical treatment.
If you have kidney stones on the move, you may also experience bloody urine, fever and chills, nausea and vomiting as well as a constant urge to urinate.
Once you’ve had a stone, you have a 50% chance of developing another one within the next five years, the NIH says. This risk generally increases with advancing age.
Someone who is at risk for kidney stones should drink at least 12 glasses of water each day, especially during the summer, Dr. Monga says.
“Drinking plenty of water will help to dilute your body liquids, as well as calcium oxalate, the substance that forms most types of kidney stones,” Dr. Monga says. “Making sure you are drinking enough water is one way you can help to prevent development of renal stones.”