Kidney stone pain (renal colic) is typically a sudden, severe, wave-like pain in the flank or back, often moving toward the groin. It may be accompanied by nausea, blood in the urine and urinary urgency. Fever alongside this pain requires emergency assessment.
- Blood in the urine with an inability to pass urine, or large clots blocking flow
- Fever alongside urinary symptoms or severe flank pain
- Sudden severe pain with no relief after 30 minutes
- Dizziness, fainting or signs of significant blood loss
Kidney-stone pain—renal colic—is often intense and difficult to ignore. Yet flank pain can also come from infection, the spine, bowel, gallbladder, vascular conditions or reproductive organs. Symptoms suggest a stone, but imaging and clinical assessment confirm it.
The classic pain pattern
- Sudden severe pain in the flank or back below the ribs
- Pain that comes in waves as the ureter contracts
- Movement toward the lower abdomen and groin
- Restlessness—many patients cannot find a comfortable position
- Nausea or vomiting
- Urinary urgency, frequency, burning or visible blood
Emergency red flags
- Fever, chills or feeling septic
- One kidney, kidney transplant or known poor kidney function
- Pregnancy
- Pain with inability to pass urine
- Persistent vomiting or dehydration
- Uncontrolled pain despite medication
- Fainting, severe weakness or a pulsating abdominal sensation
Around 1 in 10 people will experience a kidney stone in their lifetime. Men are affected roughly twice as often as women, and recurrence is common without dietary or lifestyle changes.
Why fever plus a stone is dangerous
An obstructed infected kidney can deteriorate rapidly and may need urgent drainage and intravenous antibiotics. Do not wait for a routine clinic appointment when severe pain is accompanied by fever or systemic illness.
How stones are diagnosed
Assessment may include urine and blood tests plus imaging. Non-contrast CT is commonly used in adults, while ultrasound may be preferred in pregnancy or selected situations.
Treatment depends on size and location
Small stones may pass with pain control, hydration guidance and selected medication. Larger or impacted stones may need shockwave treatment, ureteroscopy and laser fragmentation, or percutaneous surgery. Antibiotics alone do not relieve an infected obstruction.
After the acute episode
Stone analysis and a metabolic evaluation can identify preventable risks, especially after recurrent stones, bilateral stones, young age, family history or unusual stone types. Generic advice to “drink more” should be personalised to medical circumstances.
Frequently asked questions
Yes. It often occurs in waves, though pain patterns vary.
Yes. Absence of visible blood does not rule out a stone.
Do not force excessive fluid during acute obstruction or vomiting; follow medical advice.
It depends on size, location and anatomy. Some pass within days; others take weeks or require treatment.
Go urgently for fever, uncontrolled pain, persistent vomiting, reduced urine, one kidney, pregnancy or severe illness.
Speak to Mr Torath Ameen
If you have concerns about urological symptoms or would like an expert opinion, book a consultation at our London or Hertfordshire clinics.
This article is intended for general patient education only. It does not constitute medical advice and may not apply to every individual's circumstances. Clinical decisions should always be made in consultation with a qualified healthcare professional. If you are concerned about your health, please seek prompt medical assessment.