Yes, a fever or chills during a kidney stone episode is a serious clinical sign that usually indicates a secondary infection, which can quickly lead to a life-threatening condition called urosepsis. While a standard kidney stone causes intense pain, it does not typically cause a high temperature on its own. If you have a stone and begin to feel shivery, feverish, or generally ‘flu-like’, it suggests that the stone is blocking the flow of urine and allowing bacteria to multiply behind the obstruction. In the UK, this is considered a surgical emergency requiring immediate hospital assessment.
What We will cover in this Article
- The link between urinary obstruction and infection
- Why ‘rigors’ (uncontrollable shaking) are a critical warning sign
- The progression from an infected stone to urosepsis
- Differentiating between a standard stone and an infected one
- How ‘struvite’ stones are uniquely linked to bacteria
- Emergency clinical steps for managing an infected stone
The Danger of the ‘Blocked and Infected’ Kidney
A kidney stone becomes significantly more dangerous when it causes an obstruction. Under normal circumstances, urine flows freely, washing away bacteria. However, when a stone blocks the ureter, the urine behind the stone becomes stagnant much like a pond rather than a flowing river.
If bacteria are present in this stagnant urine, they can multiply rapidly. Because the urine is under high pressure due to the blockage, these bacteria and their toxins can be forced into the bloodstream. This is the biological trigger for a fever. A fever is your body’s attempt to fight this systemic invasion, and chills (or rigors) occur as your muscles rapidly contract and relax to generate heat.
- Urinary Stasis: Stagnant urine provides a breeding ground for bacteria.
- Pyelonephritis: A serious infection of the kidney tissue itself.
- Pyonephrosis: A critical condition where pus collects in the obstructed kidney.
Identifying the Warning Signs: Fever and Rigors
In the UK, urologists categorise kidney stone patients into ‘stable’ and ‘unstable’ based on the presence of infection markers. If you have a stone, you must monitor for the following ‘red flag’ symptoms:
- High Temperature: A fever of 38°C (100.4°F) or higher.
- Chills and Rigors: Uncontrollable shivering or feeling very cold despite having a high temperature.
- Tachycardia: A racing heart rate or feeling short of breath.
- Confusion: Feeling disoriented or unusually tired, which can be an early sign of sepsis.
While the pain of a stone is agonizing, it is the fever that signals a risk to your life. An infected, obstructed kidney can lead to permanent renal damage or septic shock within hours if the blockage is not relieved.
The Role of ‘Infection’ (Struvite) Stones
Specific bacteria produce an enzyme that changes the chemistry of your urine, making it highly alkaline. This allows magnesium, ammonium, and phosphate to crystallise into large, fast-growing stones. Because these stones are porous, they can ‘trap’ bacteria inside them, making the infection very difficult to clear with antibiotics alone. These stones often require surgical removal to fully eliminate the source of the recurring fevers.
Table: Standard Stone vs. Infected Stone
| Symptom | Standard Kidney Stone | Infected/Obstructed Stone |
| Pain | Sharp, wave-like (Colic) | Intense, constant, or dull ache |
| Temperature | Normal | High Fever (≥38°C) |
| Shivering | None (may sweat from pain) | Rigors/Uncontrollable chills |
| Nausea | Common during pain waves | Frequent and persistent |
| Urgency | Call GP or 111 | Call 999 or go to A&E |
To Summarise
While kidney stones are famous for their pain, the development of a fever or chills is the most dangerous symptom of all. It indicates that the stone has caused a blockage and a subsequent infection that is threatening to enter your bloodstream. In the UK medical system, ‘fever plus stone’ equals an immediate hospital admission. Early treatment with intravenous antibiotics and surgical drainage of the kidney is essential to prevent urosepsis and ensure a safe recovery.
If you experience severe pain in your side accompanied by a fever, chills, or shivering, call 999 or go to your nearest A&E immediately. This is a medical emergency.
Can a kidney stone cause a fever without an infection?
No. A high temperature is almost always a sign that bacteria have triggered an immune response. Pain alone does not typically cause a fever.
What should I do if I feel shivery but my temperature is normal?
Shivering (rigors) often precedes a spike in temperature. If you have stone pain and are shivering, you should seek urgent medical advice via 111 or A&E.
Will antibiotics fix a blocked, infected kidney?
Antibiotics are essential, but they often cannot reach the site of the infection if the urine flow is blocked. The ‘blockage’ usually needs to be bypassed with a small tube (stent) or a drain.
Why is an infected stone an emergency?
Because the kidney is highly vascular, bacteria in a blocked kidney can enter the bloodstream very quickly, leading to septic shock.
Can I take paracetamol to lower the fever?
Paracetamol can lower a fever, but it will not treat the underlying blockage or infection. You must still seek emergency care even if the fever temporarily drops.
How do doctors check for an infection?
In the UK, clinicians will use a combination of blood tests (looking for high white cell counts), urine cultures, and a CT scan to check for a blockage.
Are children more at risk for infected stones?
Children can deteriorate very quickly when an infection is present; any fever in a child with a suspected stone must be treated as an emergency.
Authority snapshot
This article was reviewed by Dr. Stefan Petrov, a UK-trained physician with an MBBS and postgraduate certifications including ACLS and BLS. Dr. Petrov has extensive experience in the NHS managing urological emergencies and identifying the early ‘red flags’ of urosepsis. This guide follows clinical standards to ensure that life-threatening symptoms are clearly identified for patient safety.
