Six common signs of kidney stones

Around one in 10 people in the UK develop kidney stones. However, many people don’t realise that their symptoms are caused by kidney stones and endure symptoms for longer than is necessary. Knowing the signs to spot can ensure you get a diagnosis and treatment as soon as possible.

What are kidney stones?

Kidney stones affect people of all ages, although they are most common between the ages of 20 and 50 years. They occur when the waste that your kidneys filter from your blood forms tiny crystals. Over time, these crystals can attach to other crystals, ultimately developing into kidney stones. 

Kidney stones range in size, from as small as a grain of sand to stones several millimetres or even centimetres in size. Small kidney stones often do not cause any symptoms — they pass out of your body via your urine without any pain or discomfort. However, larger kidney stones can cause both short and long-term symptoms and in some cases, can permanently damage your kidneys. 

Kidney stone symptoms

1. Pain in your midsection

Your kidneys are located just below your ribcage, on either side of your spine. Pain from kidney stones, therefore, causes lower back pain and/or pain on the side of your stomach. 

This pain is intense and occurs when a kidney stone gets stuck trying to pass out your body — this is called renal colic. The kidney stone usually gets stuck in the tube that connects your kidneys to your bladder (ureter). The size of your kidney stone doesn’t always relate to the amount of pain you experience — small stones can be more painful than large stones. 

Pain caused by renal colic can come and go in waves and can also change location as the stone moves. You may notice that the pain radiates towards your groin and stomach. 

2. Pain when urinating

When your body passes out a kidney stone, the stone must first exit your kidney, go through your ureter and pass into your bladder. At the point when the stone passes from your ureter to your bladder, you may experience pain or a burning sensation when urinating. 

3. Recurring urinary tract infections (UTIs)

When kidney stones cause a blockage anywhere along your urinary tract, you’re more likely to experience recurring UTIs. Common UTI symptoms often overlap with symptoms of kidney stones and include: 

• Blood in your urine 
• Cloudy, dark or strong-smelling urine
• Fever and chills
• Needing to urinate more often or more urgently than usual
• Pain in your lower back or stomach area
• Pain or a burning sensation when urinating

4. Blood in your urine

As a kidney stone passes through your urinary tract, which includes your ureter, bladder and the tube that carries urine out of your bladder (urethra), it can damage the cells it brushes past. This can cause bleeding, which you may notice in your urine — blood may appear red, pink or brown. 

In some cases, the level of blood in your urine is so low that it can’t be seen by eye and instead a urine test is needed. 

5. Fever and chills

A serious complication of kidney stones is an infection in your kidney or elsewhere in your urinary tract. If you are in pain and have a fever with or without chills, you should seek urgent medical help.  

6. Nausea and/or vomiting

Your gut and your kidneys share common nerve pathways. This is why pain caused by kidney stones can cause a reaction in the nerves that supply your gut, leading to an upset stomach. This can trigger nausea and vomiting. 

What to do if you think you have kidney stones

If any of the above symptoms sound familiar, you should see your GP. They may be able to diagnose kidney stones based on your symptoms and medical history alone. However, in some cases, you may need tests, such as blood tests, urine tests, or imaging tests (eg CT scan or X-ray). 

With a diagnosis, you can then get the treatment you need to resolve your symptoms. For small kidney stones, painkillers and drinking lots of water may be enough to pass the kidney stones out of your body. If you have larger kidney stones, there are several other non-surgical treatments, including medication and lithotripsy. If these treatments aren’t appropriate, keyhole surgery may be needed.