Kidney stones
The doctor who has seen you thinks you may have a kidney stone (renal calculus) and you will be investigated to confirm or exclude this.
What are kidney stones?
The kidneys filter your body’s blood and remove waste and chemicals to make urine. Some chemical crystals like calcium can clump together to form stones in the kidney.
Who gets kidney stones?
- Men get them more commonly than women
- Kidney stones may be recurrent in some people
- If salts in your blood become more concentrated due to loss of water (due to exercise, dehydration or hot climates) then you may get kidney stones
- Some people have underlying medical problems that cause high levels of certain chemicals that form stones
- Certain medications may make you prone to having kidney stones (eg water tablets or diuretics, some medicines used for chemotherapy)—however, not everyone taking these medications will get stones
What are the symptoms you may experience?
Some people have no symptoms and kidney stones are found incidentally.
However some patients may experience the following:
- Pain or “renal colic” is the severe pain people get when the stone is squeezed down the ureter (the tube connecting the kidney to the bladder)
- You may have blood in the urine (haematuria) that may be visible, or may be detected using a bedside urine test—this is caused by the stone “rubbing” against the wall of the ureter
- Urine infections can occur with stones and may cause fever and pain on passing urine
How will you know if you have a stone?
The doctor who has seen you will organise further tests to confirm you have a stone.
These may include:
- Urine tests to check for blood and any signs of associated infection
- Blood tests to look at your kidney function, blood salts and for any signs of infection
- X-rays to see if any stones are visible though not all stones will be
- A CT or ultrasound scan—these may be done at a later time
What should you do if you are suspected of having kidney stones?
If you are thought to have a kidney stone then treatment consists of:
- Pain relief such as anti-inflammatory medication (ibuprofen or diclofenac) and/or other painkillers (paracetamol or co-dydramol)—you may have been given stronger painkillers on first evaluation in the Emergency Department (A&E)
- Fluids—you must drink enough to encourage good urine flow (aim for clear urine as yellow or dark urine means concentrated urine)
What if you have had a kidney stone confirmed?
If we have confirmed that a stone is present then you need to continue with pain relief as needed and adequate fluids. In addition to this:
- You may be given another drug to relax the muscles to aid stone passage for a short term (eg tamsulosin)
- Most stones are small (less than 5mm) and will most likely pass within a month (often sooner)—you should arrange follow-up through your GP
- Some stones are larger and may take longer to pass, or can occasionally block the urine flow and cause problems with your kidney—you may need to be seen by a kidney specialist (urologist) immediately or in a follow-up clinic
If a stone has not been confirmed what happens next?
If you have been seen but not yet had a stone confirmed you may be allowed home if you are feeling better and asked to return for further imaging. This may involve a CT scan or an ultrasound.
While at home please ensure:
- You are keeping well hydrated and drinking enough—aim for clear urine
- You are taking regular painkillers to keep comfortable
- You must seek medical advice or return to A&E if:
- Your pain is not controlled by your painkillers
- Passing urine is difficult
- You develop symptoms of an infection such as fever or pain passing urine
- You start passing visible blood in your urine