Kidney Pain vs Back Pain: How to Tell the Difference
Medically Reviewed by Dr. Pedro Yelamo Vera, MD
Licensed Physician No. 484814280 · Official Medical College of Bizkaia (Spain)Last reviewed: 31 October 2026
Kidney pain vs back pain: where each one hurts, the signs of a kidney stone or kidney infection, and the red flags that need 112 or a doctor today.
You don't have to figure this out alone
Dr. Pedro Yelamo Vera is an independent, bilingual GP licensed in Spain. Book a 15-minute video consultation in English or Spanish for €50, with a private electronic prescription issued under Spanish law when clinically appropriate.
Kidney pain vs back pain comes down to where it hurts and what comes with it. Kidney pain is usually felt deep in one side or the back, just under the ribs. It often comes with fever, feeling sick, or changes when you pee. Back pain from muscles or joints is far more common. It usually follows a strain and has no fever or urinary symptoms.
- Your kidneys sit high in the back, just under the lower ribs, one each side of the spine.
- Kidney pain is usually one-sided, deep and under the ribs. Fever or urinary symptoms point to the kidney.
- A kidney stone causes severe pain in waves that can spread to the groin. You often cannot keep still.
- A kidney infection causes a high temperature, shivers, feeling sick and pain in the side or back.
- Sudden, severe pain in the tummy or back, especially if you are over 65 or smoke, needs 112.
Dr. Pedro Yelamo Vera is a GP licensed in Spain (Colegiado No. 484814280).
For a medical emergency, call 112 or go to the nearest local emergency department. Do not wait for a video consultation or an online reply.
Where do you feel kidney pain?
Your kidneys are two small organs at the back of your body. They sit just below the lower ribs, one on each side of the spine. Mayo Clinic describes kidney pain as a dull ache just below the ribs, along your side or back. It most often affects only one side.
Doctors call this area the flank. In Spain you will hear dolor de riñones or dolor en el costado. But Mayo Clinic also notes that pain in this area often has causes that have nothing to do with the kidneys. Where it hurts is only one clue.
How is kidney pain different from back pain?
No single sign settles it. A doctor looks at the whole picture. These are the usual patterns:
- Where it is. Kidney pain is higher and to one side, under the ribs. Ordinary back pain is often lower down, across the lower back.
- What started it. Back pain often follows lifting, a strain or a long day bent over. Kidney pain usually has no such trigger.
- Movement. Muscle pain often changes when you bend, twist or change position. Kidney stone pain does not ease when you lie still.
- Other symptoms. Mayo Clinic says fever and urinary symptoms often come with kidney pain. They are rare with simple back pain.
Urinary symptoms include pain or burning when you pee, peeing more often, and dark, cloudy or bloody pee.
What does a kidney stone feel like?
A small stone may cause no pain at all. The trouble starts when a stone moves into the tube that drains the kidney. Doctors call the pain renal colic (cólico nefrítico or cólico renal in Spain). Mayo Clinic describes:
- Severe, sharp pain in the side and back, below the ribs.
- Pain that spreads to the lower tummy and groin.
- Pain that comes and goes in waves.
- Feeling or being sick.
- Pain or burning when you pee, or pink, red or brown pee.
Many people pace about, unable to find a comfortable position. That is quite unlike muscle pain, which usually eases when you rest.
Most stones pass in the urine without treatment. A Guy's and St Thomas' NHS leaflet says this usually happens within 4 weeks. For pain relief, the UK's NICE guideline recommends an anti-inflammatory painkiller (an NSAID) first. It advises against antispasmodic medicines for this pain. NICE also advises a low-dose CT scan for adults, and an ultrasound first for children and pregnant women.
What does a kidney infection feel like?
A kidney infection (pielonefritis) usually starts as a bladder infection that travels up to the kidney. The NHS lists these symptoms:
- A high temperature, or feeling hot, cold or shivery.
- Pain in your lower back or side.
- Feeling or being sick, and sometimes diarrhoea.
- Aching muscles and flu-like symptoms.
- Pain, burning or stinging when you pee, needing to pee more often, and dark or cloudy pee.
Children may wet the bed or be drowsy. The NHS warns that a child under 2 may only have a high temperature.
A kidney infection needs antibiotics. Without treatment it can cause sepsis, a life-threatening reaction to infection. The NHS advises paracetamol for pain and fever. Avoid ibuprofen unless a doctor says it is fine, as it may raise the risk of kidney problems.
Pain in your side with burning when you pee, or a stone you think is passing?
You can book a video visit with a GP licensed in Spain, in English or Spanish. He goes through your symptoms, helps you tell kidney pain from back pain, and tells you whether you need a urine test, a scan or emergency care.
Could the pain be something else?
MedlinePlus lists other causes of pain in the side and back:
- Muscle spasm, disc problems or arthritis of the spine.
- A spinal fracture or a spine infection.
- Gallbladder, liver or bowel problems.
- Shingles, which can cause a one-sided rash.
An abdominal aortic aneurysm (AAA) is rare but important. It is a swelling of the main artery in the tummy. The NHS says it is most common in men aged 65 or over, in people who smoke or used to smoke, and in people with high blood pressure. It often causes no symptoms. If it bursts, it causes sudden, severe pain in the tummy or back. An older person with what feels like a first kidney stone needs a doctor to think about this.
When is kidney or back pain an emergency?
Call 112 or go to urgencias now if you have:
- Sudden, severe pain in the tummy or back, especially if you are over 65, smoke, or feel faint or dizzy.
- Pain with confusion, drowsiness or difficulty speaking.
- Loss of feeling around your genitals or bottom.
- Difficulty peeing, or wetting or soiling yourself, with back pain.
- Pain, tingling, weakness or numbness in both legs.
- Chest pain, or back pain that started after a serious accident.
Mayo Clinic also advises emergency care for sudden, serious kidney pain, with or without blood in your pee. Do not drive yourself.
When should you see a doctor today?
Get medical help today, without waiting, if you have side or back pain with:
- A high temperature, shivers, or a temperature below 36°C.
- Blood in your pee.
- Feeling or being sick.
- Pain so bad that you cannot sit still.
- No pee all day.
- Pregnancy.
Pain from a stone together with fever, vomiting you cannot stop, or being unable to pee means going to urgencias. A blocked, infected kidney needs hospital care.
What helps ordinary back pain?
Most back pain is not serious. The NHS says it often gets better on its own within a few weeks. These steps help:
- Keep moving. Gentle walking, swimming or yoga help more than bed rest.
- An anti-inflammatory painkiller such as ibuprofen may help. The NHS says paracetamol on its own is not recommended for back pain. Ask a pharmacist which suits you.
- Stop any exercise that makes the pain worse.
See a GP if the pain has not improved after a few weeks, is worse at night, or comes with weight loss you cannot explain. Also see a GP if it starts between the shoulder blades, or there is a lump or swelling.
Talking it through with a doctor by video
Dr. Yelamo is a GP licensed in Spain. He sees adults, children and pregnant patients by video, every day from 07:30 to 20:30 (Spain time). In the visit he will:
- Ask where the pain is, how it started and what makes it better or worse.
- Ask about fever, sickness and any change when you pee.
- Tell you whether it sounds like your back, a stone or an infection, and whether you need a urine test, a scan, an in-person exam or urgencias.
He does not promise any test or prescription before the visit. Where clinically appropriate, following a genuine evaluation. Treatment and prescriptions are issued solely at the doctor's discretion based on evidence-based clinical guidelines.
A prescription is never guaranteed: it is issued only where clinically appropriate after a genuine evaluation, as a private electronic prescription under Spanish law. This service is for urgent, non-emergency care. In an emergency, call 112.
See how the Urgent Care video visit works. It lasts 15 minutes and costs €50.
This guide is general information. It does not replace a consultation with your doctor.
Frequently asked questions
How can I tell if my back pain is my kidneys?
Kidney pain is usually deep, on one side and just under the ribs. It often comes with fever, feeling sick or pain when you pee. Back pain from muscles usually follows a strain and has none of these.
What does kidney stone pain feel like?
Severe, sharp pain in the side and back, below the ribs. It comes in waves and can spread to the lower tummy and groin. Many people cannot sit still.
Can a kidney infection cause back pain without fever?
It can, but fever, shivers and feeling sick are typical. A young child may have only a high temperature. Side pain with burning when you pee needs a doctor's check.
Is kidney pain on the left or right side?
It can be either, depending on which kidney is affected. It most often affects one side only.
When is back pain an emergency?
Call 112 for sudden, severe pain in the tummy or back, numbness around the genitals or bottom, loss of bladder or bowel control, weakness in both legs, or confusion with a fever.
Can I have a kidney stone in pregnancy?
Yes. Pregnant women with side pain, fever or urinary symptoms should see a doctor today. Doctors use an ultrasound scan rather than CT in pregnancy.
Sources
- Mayo Clinic: Kidney pain
- Mayo Clinic: Kidney stones, symptoms and causes
- NHS: Kidney infection
- NHS: Back pain
- NHS: Abdominal aortic aneurysm
Related guides
Medical Citations & Sources
This content is written and reviewed by a licensed physician with reference to the following official health authorities.
