They can be excruciatingly painful – but what exactly are kidney stones? And what can you do about them?
By Dr Rebecca McKenzie
They have made it onto the list of top 20 most painful conditions according to the NHS, alongside broken bones, appendicitis and slipped discs, but what causes kidney stones – and how do you know if they are responsible for the pain you are experiencing?
We asked Dr Rebecca McKenzie, GP at Your Doctor, for the lowdown on kidney stones:
What causes kidney stones?
Kidney stones are caused by waste products such as calcium, ammonia or uric acid in the blood, which occasionally build up to form crystals that collect inside the kidney system.
Kidney stones are quite common and most often affect people aged 30 to 60.
This is more likely to happen if you don’t drink enough fluids, if you’re taking some types of medication, or if you have a medical condition that raises the levels of certain substances in your urine.
Kidney stones come in a variety of sizes, shapes and colours. Some are like grains of sand, while in rare cases others can grow to the size of a golf ball.
Who is at risk of kidney stones?
Kidney stones are quite common and most often affect people aged 30 to 60. They affect about one in 10 women and three in every 20 men.
You’re more likely to get kidney stones if:
- You eat a high-protein, low-fibrediet
- You are inactive or bed-bound
- You have a family history of kidney stones
- You have had several kidney or urinary infections
- You only have one fully working kidney
- You have had surgery on your digestive system
- You suffer from a bowel disease, such as Crohn’s disease
Can medications cause kidney stones?
There is unfortunately evidence to suggest that certain medications may increase your risk of developing recurrent kidney stones. These include aspirin, antacids, diuretics, certain antibiotics, certain antiretroviral medication and some anti-epileptic medication.
Symptoms of kidney stones
Kidney stones can develop in one or both kidneys, but don’t always cause problems. Small kidney stones may go undetected and be passed out painlessly in your urine. However, a stone can block part of the urinary system, such as the kidney, ureter or urethra, and can cause severe pain in the abdomen or groin, sometimes causing a urinary tract infection (UTI).
Kidney stones symptoms include:
- A persistent ache or pain in your lower back, back or side of your abdomen, groin, testicles or scrotum
- Difficulty lying still
- Needing to urinate more often
- Pain when urinating weeing
- Smelly, cloudy urine or blood in your urine
- Feeling generally unwell
- If a kidney infectionis also present, you are likely to have a fever with a high temperature, the chills and weakness
Diagnosing kidney stones
Your GP will usually be able to diagnose kidney stones from your symptoms and medical history, particularly if you’ve had kidney stones before. You will normally be asked to take a urine test and blood tests, to check that your kidneys are working properly, and to also check the levels of substances that could cause kidney stones, such as calcium.
Your GP will usually be able to diagnose kidney stones from your symptoms and medical history.
It is helpful to try to urinate through some gauze or a stocking, to try to collect the stone, as analysis of this will make the diagnosis easier and help find the treatment that is best for you.
In severe cases, you may be referred to a urologist for an x-ray, CT scan or ultrasound scan.
Treatment for kidney stones
If your kidney stones are generally less than 4mm in diameter, they can usually be passed at home while managed with painkillers. Larger stones may need to be broken up using ultrasound or laser energy.
Occasionally, keyhole surgery may be needed to remove very large kidney stones directly. You might need to take antiemetic (anti-sickness) medication. Try to drink a lot of water to keep yourself hydrated.
You may require admission to hospital if you experience the following:
- The pain is severe
- You are at risk of kidney failure
- Your symptoms persist, despite painkillers
- You are dehydrated and vomiting too much to keep fluids down
- You are pregnant
- You are over 60 years of age
How to prevent kidney stones
It is estimated that up to half of all people who have had kidney stones will experience them again within the following five years. However, there are measures you can take to help stop them returning:
✔️ Drink lots of water
The best way to prevent kidney stones is to make sure you drink plenty of water each day, to avoid becoming dehydrated and to stop a build-up of waste products. Drink more when it’s hot or when you’re exercising, to replenish fluids lost through sweating.
✔️ Dietary changes
If your kidney stone is caused by too much calcium, you may be advised to reduce the amount of oxalates in your diet, which prevent calcium being absorbed by your body and can accumulate in your kidney to form a stone. Foods that contain oxalates include beetroot, chocolate, asparagus, almonds, peanuts, cashew nuts, soy products and grains such as oatmeal, wheat germ and whole wheat.
Don’t reduce the amount of calcium in your diet unless your GP advises you to, as it is very important for maintaining healthy bones and teeth.
✔️ Uric acid
To avoid developing a uric acid stone, you should reduce the amount of meat, poultry and fish in your diet. Try the Flexitarian diet.
You may be prescribed medication to change the levels of acid or alkaline in your urine. However, some medication you are on may be causing your kidney stones and will need to be reviewed by your GP.