If you have a kidney stone that is very small, it is unlikely to cause many symptoms. It may even go undetected and pass out painlessly when you urinate.

Symptoms usually occur if the kidney stone:

• gets stuck in your kidney
• starts to travel down the ureter (the tube that attaches each kidney to the bladder) – the ureter is narrow, and the kidney stone causes pain as it tries to pass through
• causes an infection

In these cases, common symptoms of kidney stones include:

• persistent ache in the lower back, which is sometimes also felt in the groin – men may have pain in the testicles and scrotum
• periods of intense pain in the back or side of your abdomen, or occasionally in your groin, which may last for minutes or hours
• feeling restless and unable to lie still
• nausea (feeling sick)
• needing to urinate more often than normal
• pain when you urinate
• blood in your urine – this may be caused by the stone scratching the kidney or ureter

Blocked ureter and kidney infection

If a kidney stone causes a blocked ureter, this can lead to a kidney infection. This is because waste products cannot pass, which may cause a build-up of bacteria.

Symptoms of a kidney infection are similar to symptoms of kidney stones, but may also include:

• a high temperature (fever) of 38°C (100.4°F) or over
• shivering
• chills
• feeling very weak or tired
• diarrhoea
• cloudy and bad-smelling urine

Read more information about kidney infections.