Symptoms of a kidney stone

Classic renal colic

The textbook symptom of a kidney stone passing down the ureter is renal colic. Patients describe:

• Severe loin pain starting in the flank (the side of the back, just below the ribs).
• Pain radiating forward and down around the abdomen into the groin, and sometimes into the testicle or labia.
• Pain that comes in waves over 20 to 60 minutes and is very difficult to relieve by changing position.
• Often nausea and vomiting because of the severity of the pain.
• Restlessness - most patients cannot sit still, which is a useful clue at the bedside.

The pain is caused by the stone obstructing urine drainage and stretching the ureter and the lining of the kidney. Interestingly, the intensity of pain correlates poorly with stone size - a 3 mm stone can be excruciating while a large, long-standing kidney stone may cause no pain at all.

How the site of pain relates to the stone's position

The pain pattern often shifts as the stone moves down the ureter:

• Stone at the kidney or upper ureter: loin and flank pain, sometimes just a dull ache.
• Stone in the mid ureter: pain in the flank that radiates to the front of the abdomen.
• Stone in the distal ureter, near the bladder: pain radiating to the groin, testicle, labia or tip of the penis, and often frequency, urgency or the sensation of needing to pass urine constantly, which can be mistaken for a urinary infection.

Blood in the urine (haematuria)

Visible blood in the urine can occur but is not universal - in fact, most people with a passing stone have only microscopic haematuria that is detected on urinalysis rather than being visible to the eye. Visible blood, clots, or pink urine should always be reported to a doctor.

Other symptoms that can occur

• Burning or stinging on passing urine, particularly when a stone is sitting in the lower ureter near the bladder.
• Frequency and urgency, similar to a urinary tract infection.
• Difficulty starting the urinary stream or a sudden interruption of flow, if the stone drops into the bladder or the bladder outlet.
• Nausea or vomiting, mainly as a response to the severity of the pain.

Is it renal colic, or something else?

Kidney stone pain can mimic - and be mimicked by - other conditions. At the emergency department the differential diagnosis commonly includes:

• Musculoskeletal back or flank strain.
• Urinary tract infection or pyelonephritis.
• Appendicitis, diverticulitis, or biliary colic.
• An ovarian cyst or ectopic pregnancy in women of reproductive age.
• A leaking abdominal aortic aneurysm in older patients - any acute flank pain in an older adult should be considered carefully.

For these reasons, new severe flank pain - even if a kidney stone is suspected - is best evaluated with a CT KUB and clinical review, rather than assumed.

Kidney stones that cause no symptoms

Not all kidney stones hurt. Many are found incidentally on CT scans done for other reasons - such as an abdominal CT for back pain, a CT colonography, or a low-dose CT done during a lung cancer screening. These asymptomatic stones need a considered management plan. Some can be watched (active surveillance) while others - particularly larger or lower-pole stones, or stones in a solitary kidney - are best treated electively to avoid a future emergency presentation.

What to do if you think you have a kidney stone

1. Assess urgency

   If you have any of the warning signs above (fever, severe uncontrolled pain, inability to pass urine, significant bleeding), do not wait for an appointment - go to your nearest emergency department.

2. See your GP

   If pain is tolerable and you have no warning signs, see your GP the same or next day. They will check your urine, arrange bloods, and most often organise a CT KUB.

3. Get referred

   If a stone is confirmed, your GP can refer you to Dr Kooner's rooms for definitive assessment and treatment planning. See the For GPs page for referral details.

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