Kidney stones have been steadily increasing over the last 30 years, but one unexpected reason is due to global warming.
A paediatric urologist Gregory Tasian and his team analysed over 60,000 medical records of people with kidney stones in major cities in the US and found that rising temperatures may be to blame.
He said: "Kidney stone prevalence has already been on the rise over the last 30 years, and we can expect this trend to continue, both in greater numbers and over a broader geographic area, as daily temperatures increase. With some experts predicting that extreme temperatures will become the norm in 30 years, children will bear the brunt of climate change."
But what are kidney stones?
Kidney stones are calcium deposits that build up in the kidneys, made from waste products. Men are more likely to suffer from them.
Bupa writes: "You normally have two kidneys, which ‘clean’ your blood, and filter out water and waste products to make urine. Kidney stones can form when there is an imbalance of salts or minerals in your urine. These minerals form into crystals, which are often too small to notice, and pass harmlessly out of your body."
Small ones can take a day to six weeks to pass, while larger ones may not flush without help. Problems arise when they are too big to pass through undetected - causing a fair amount of pain as they need to pass through your bladder. If they are too big, you may have to have surgery to break them down.
A major problem is when the kidney stone blocks your ureter. Bupa adds: "If the kidney stone completely blocks your ureter, it can stop the flow of urine. Without treatment to remove the kidney stone, this can lead to permanent damage to your kidneys within a number of weeks.
"If a kidney stone is blocking your ureter, this can also cause severe infection, which can become life-threatening without treatment. Signs of an infection include having a fever and cloudy urine. It's important that you seek urgent medical attention if you have these symptoms."
Why all the focus on kidney stones? Because it's surprisingly common. The NHS says: "It is estimated that up to half of all people who have had kidney stones will experience them again within the following five years.
"To avoid getting kidney stones, make sure you drink plenty of water each day so that you don't become dehydrated. It is very important to keep your urine diluted to prevent waste products forming into kidney stones."
HuffPost US blogger Leslie Spry, spokesman for the US-based National Kidney Foundation advises: "When it comes to dietary choices, the Dietary Approaches to Stop Hypertension (DASH) diet reigns supreme, according to a new study published in the March issue of the National Kidney Foundation's American Journal of Kidney Diseases. The DASH diet is high in fruits, vegetables, legumes and nuts, moderate in low-fat dairy products, and low in animal proteins, refined grains and sweets. In addition to being a well-balanced low salt diet, it may reduce your risk for developing kidney stones.
"I've long touted the DASH diet as a kidney-friendly diet that has many health benefits, including reducing high blood pressure and helping to prevent kidney stones, so I'm very excited to share this new research with you. The study authors found that compared with following a low-oxalate diet -- the frequently prescribed diet for kidney stone prevention and treatment -- a DASH-style diet was more effective at reducing urinary risk markers for calcium oxalate kidney stone formation, the most common type of kidney stone (more than 80 percent)."
How does that translate into real life? If you are having a heavy week of boozing, make sure you drink water with each alcoholic beverage, and definitely replenish the night before.
If you want to prevent kidney stones, Bupa advises:
- Don’t eat more than 3g of salt a day – don’t add it to your food and avoid processed foods.
- Cut down on foods that have high levels of oxalate – such as chocolate, tea, rhubarb, spinach, nuts and strawberries.
- Eat less meat, fish and poultry – liver, kidneys, herrings with skin, sardines, anchovies and poultry skin increase the amount of uric acid in your urine.
- Don’t take supplements containing calcium, vitamins A, C or D.
Here are some of the symptoms that you may have a kidney stone: