Think you might have kidney stones? We explain the symptoms, causes, treatment & advice to help prevent them
More than one in 10 people are affected by kidney stones at some point in their life, but many are unsure about what they are and what symptoms to look out for.
Here, we give you a rundown of the things you need to know, including the main symptoms and what to do if you think you have kidney stones.
What do the kidneys do?
Before we get into what kidney stones are, it’s important to understand the role kidneys play in the body.
The kidneys are two bean-shaped organs that sit just below the rib cage on either side of the spine. They’re the size of an adult fist, measuring around 10cm (four inches) in length. Although they’re not very big, they’re complex and have a very important role in the body.
The main responsibility of the kidneys is to remove waste products and excess fluid from the blood. Once the waste products have been removed, the filtered blood is then returned to the body and the waste products are passed out of the body as urine when you wee.
The kidneys are also responsible for:
• Maintaining a healthy balance of water, salts and minerals in your blood
• Releasing hormones that regulate blood pressure, making red blood cells and keeping bones healthy
Although most people have two kidneys, it’s possible to live a long, healthy life with just one functioning kidney.
What are kidney stones?
Kidney stones are hard, stone-like lumps that can develop in one or both kidneys. Some are as small as a grain of sand, while others can differ in diameter (between a few millimetres and a few centimetres), but they can be extremely painful.
They’re usually found in the kidneys or the ureter (the tube that connects the kidneys to your bladder) and small kidney stones may be found in your urine. They’re quite common, often affecting people aged 30 to 60 years, typically occurring in around three in 20 men and two in 20 women.
What are the symptoms of kidney stones?
Very small kidney stones may be passed in your urine when you wee and often go undetected therefore making them unlikely to cause any symptoms. However, larger kidney stones can cause symptoms such as:
• Pain in the side of your abdomen (tummy) or groin – some men may notice pain in their testicles
• A high temperature, or fever
• Severe pain in the back or side of your abdomen that comes and goes
• Feeling sweaty
• Blood in your urine
• Urinating more often than usual or pain when you urinate
• Feeling sick or vomiting
• A urinary tract infection
If you have any of these symptoms, speak to your GP as soon as possible.
What causes kidney stones?
As we mentioned earlier, the kidneys role is to remove waste products from the blood. Kidney stones often form if there’s a build-up or imbalance of waste chemicals in the body, and in some cases, certain medical conditions can also lead to a high level of these chemicals in your wee. This rise can cause crystals to form, which may build-up to stone-like lumps, known as kidney stones.
This can happen for a number of reasons, including:
• Not drinking enough fluids – take a look at our top tips for drinking more water
• Taking certain medications
• Having a medical condition, like kidney disease, that raises the levels of certain substances in your urine
After a kidney stone has formed, your body will try to pass it through the ureter when you wee. If the kidney stones are larger, they can cause irritation as they come through the ureter, blocking the flow of urine. This can develop into an infection and cause intense pain in your back.
How are kidney stones diagnosed?
A GP may be able to diagnose kidney stones by asking you about your symptoms and medical history. They may also carry out some tests, including:
• Urine tests to check for an infection and pieces of stones
• An examination of any stones you’ve passed in your wee
• A blood test to check your kidneys are working properly and to check the levels of substances (like calcium) that could cause kidney stones
Your GP may also advise you how to collect a kidney stone so it can be analysed. This can make the diagnosis easier and means your GP can determine which treatment method will be most beneficial to you.
If you’re experiencing severe pain that may be caused by kidney stones, your GP may refer you to the hospital for an urgent scan:
• Adults may have a CT scan
• Pregnant women may have an ultrasound scan
• Children (and those under 16) are usually offered an ultrasound, however if this scan doesn’t find anything, a low-dose, no-contrast CT scan may be considered.
Kidney stones treatment
Following a diagnosis, your GP will discuss lifestyle interventions and your treatment options, if appropriate, depending on the severity of the kidney stones.
Treating small kidney stones
Most kidney stones are small enough to be passed through your wee and can usually be treated at home. Kidney stones can be painful until they’re passed which usually takes one to two days. To help relieve the pain, your GP may offer you a non-steroidal anti-inflammatory drug (NSAID), if it’s suitable for you.
Your GP may also recommend the following to help ease your symptoms:
• Drinking plenty of fluids throughout the day until the stones have cleared
• Anti-sickness medication
• Alpha-blockers – a type of medication to help the stones pass
If your kidney stones are causing severe pain, speak to your GP. They may send you to hospital for further tests and treatment.
Treating large kidney stones
If your kidney stones are too large to pass naturally, they’re often removed via surgery. There are three main types of surgery, depending on the size and location of your kidney stones. These include:
• Shockwave lithotripsy (SWL)
• Ureteroscopy
• Percutaneous nephrolithotomy (PCNL)
Shockwave lithotripsy (SWL)
This type of treatment involves using ultrasound (high frequency sound waves) to locate the kidney stone(s). Shock waves are sent to the stone(s) to break it into smaller pieces so it can be passed when you wee. You may be offered pain relief beforehand as this treatment can be a little uncomfortable.
You may need more than one session of SWL to treat your kidney stones, depending on their size.
Ureteroscopy
A ureteroscopy is the most frequently used surgical treatment for kidney stones that have not passed in the ureter or are unlikely to pass naturally. This involves being put under general anaesthetic to pass a long, thin tube called a ureteroscope into the urethra (the tube urine passes through on its way out of the body) and into the bladder.
It can then be passed up the ureter to the stone, where the surgeon may either try to break up the stone using another instrument or use laser energy to break it down into small pieces to be passed naturally when you wee.
Percutaneous nephrolithotomy (PCNL)
A PCNL is carried out under general anaesthetic and involves making a small incision into the back. A thin telescopic instrument called a nephroscope is then passed through this incision and into the kidney. The kidney stone is either pulled out or broken into smaller pieces using a laser or pneumatic energy.
Complications of kidney stones treatment
In some cases, there may be complications after treating larger kidney stones and your surgeon will discuss these risks with you prior to treatment and answer any questions you may have.
These complications can differ depending on the size of the kidney stones and the type of treatment you have, but may include:
• Sepsis – an infection that spreads through the blood causing symptoms throughout the whole body
• A blocked ureter caused by stone fragments
• An injury to the ureter
• A urinary tract infection (UTI)
• Bleeding during surgery
• Pain
Can I prevent kidney stones?
The best way to reduce the risk of developing kidney stones is to make sure you drink enough water each day to avoid becoming dehydrated. Typically, adults should aim to drink around six to eight glasses of water per day, however if you’re trying to prevent kidney stones from returning, the NHS recommends drinking up to 3 litres (5.2 pints) of fluid throughout the day, every day. This includes water, tea and coffee.
Other tips include:
• Adding fresh lemon juice to your water
• Cutting out fizzy drinks
• Avoiding eating too much salt
A tell-tale sign that you’re drinking enough fluids is if your wee is a pale colour. If it’s too dark, you need to be drinking more. Keeping your urine clear helps to stop waste products getting too concentrated and forming stones.
You may notice that your urine is a dark yellow in the morning, this is because a build-up of waste products are produced overnight and this is completely normal.
You should also try to drink more than the recommended amount if it’s hot, you’re sweating or exercising.
What happens if I leave kidney stones untreated?
It’s important to get checked if you suspect you have symptoms of kidney stones. If left untreated, kidney stones can block the ureters or make them narrower. This increases the risk of infection, the kidney not working properly or urine building up and therefore putting strain on the kidneys.
So if you notice symptoms of kidney stones, speak to a GP for advice.
