Anthony Ofori | Medical Graduate in General Medicine | Founder, WellNest Central
Last updated: October 21, 2026
This article is for general health education and does not replace individual medical advice, diagnosis, or treatment.
An ache near your waist can make you wonder whether you strained a muscle or whether something is wrong with your kidneys. The distinction matters, but there is no reliable home test that settles it.
Kidney pain often feels deeper and higher in the back, near the sides beneath the ribs. Muscle or spine pain more often changes with movement. These are clues, not a diagnosis. Fever, urinary symptoms, the way pain started, and a clinical examination can be more useful than location alone.
If the pain is severe, you cannot pass urine, or you feel seriously unwell, seek urgent care rather than trying to identify the cause yourself.
Where is kidney pain usually felt?
Your kidneys sit toward the back of the abdomen, on either side of the spine. Pain from this area is often called flank pain. It may affect one side or both, and it can spread toward the abdomen or groin.
The American Kidney Fund’s explanation of kidney pain describes why it can be confused with back pain. Nearby muscles, joints, nerves, and other organs can all produce discomfort in overlapping areas.
That means a photograph showing “exactly where kidney pain happens” cannot confirm the cause of your own symptoms. A low ache does not automatically rule out a urinary problem, and pain beneath the ribs does not automatically identify one.
Kidney pain vs. back pain: useful clues
| Feature | A possible kidney or urinary cause | A possible muscle, joint, or nerve cause |
|---|---|---|
| Location | Deep discomfort in the flank, sometimes spreading toward the groin | Pain around the lower spine, back muscles, buttock, or leg |
| Movement | May remain uncomfortable despite changing position | Often changes with bending, twisting, lifting, or posture |
| Other symptoms | Burning urination, blood in urine, fever, chills, nausea, or vomiting may occur | Stiffness, a recent strain, or pain traveling down a leg may occur |
| Pattern | Can be an ache or severe pain that comes in waves | Can be aching, sharp, burning, or shooting |
None of these features is exclusive. Pain intensity also does not tell you which organ is involved: a muscle spasm can be intense, while some important kidney problems cause little or no pain.
When an infection or stone becomes more likely
Kidney infection
Flank pain with fever, chills, painful urination, or feeling generally ill needs prompt assessment. Nausea and vomiting can occur too. The NIDDK guide to kidney infection symptoms explains that the presentation varies with age.
Do not wait for every symptom to appear. A suspected kidney infection usually needs prescription treatment; drinking extra water alone does not treat it. Seek care promptly, particularly during pregnancy or if you have a single functioning kidney or a weakened immune system. Our kidney infection guide explains the assessment in more detail.
Kidney stones
A stone may cause sharp pain that moves from the side toward the lower abdomen or groin. Pain can come and go, and you may feel unable to get comfortable. Blood in the urine, nausea, or vomiting can accompany it.
According to NIDDK’s kidney stone guidance, difficulty passing urine and fever are also reasons for immediate medical attention. Fever with possible stone pain is especially concerning because an infection and blocked urine flow can occur together.
Would you like help understanding kidney health information and preparing questions for your healthcare team? Explore health education consultations at WellNest Central.
Which warning signs need urgent help?
Get urgent medical assessment for severe or worsening flank pain, pain with fever or shaking chills, repeated vomiting, or inability to pass urine. Call 911 if there is collapse, confusion, severe breathing difficulty, or another sign of a medical emergency.
Back symptoms have their own emergency warning signs. New loss of bladder or bowel control, numbness around the groin or buttocks, or substantial new leg weakness requires emergency assessment. Do not assume these symptoms are a kidney problem.
Pain after a major fall or accident also needs prompt care. The MedlinePlus guide to acute low back pain discusses these and other reasons to seek assessment, including unexplained fever, weight loss, or a history of cancer.
How clinicians work out the cause
Expect questions about the exact location, when the pain began, what changes it, and whether you have urinary or bowel symptoms. Mention recent injury, pregnancy, previous stones, infections, kidney disease, and all medicines you take.
Depending on the findings, a clinician may recommend a urine test, urine culture, blood tests, or imaging. Testing is selected for the suspected problem; everyone with back pain does not need a scan.
Kidney filtration tests answer a different question from a pain assessment. A creatinine result alone cannot identify why your side hurts. Our guide to eGFR, urine albumin, and urinalysis explains how these tests contribute different information.
Before an appointment, write down when the pain started, whether it travels, and any fever or urine changes. Describe what you actually noticed rather than labeling the pain as “definitely my kidneys.” This gives the clinician a clearer starting point.
What can you do while arranging care?
Avoid heavy lifting or movements that clearly aggravate the pain. If a clinician has identified an uncomplicated back strain, gentle activity is generally preferable to prolonged bed rest. That advice should not be used to dismiss unexplained flank pain.
Ask a pharmacist or clinician which pain medicine is suitable for you. Ibuprofen and naproxen are not appropriate for everyone, especially with kidney disease or dehydration. NIDDK’s advice on protecting your kidneys when using medicines explains why this matters.
Do not force large quantities of water to “flush out” the pain, particularly if you have a fluid restriction or trouble passing urine. Avoid taking leftover antibiotics or repeatedly pressing or tapping your back as a self-test.
Common questions
Can kidney pain happen without burning when I urinate?
Yes. Urinary burning is a useful clue when present, but its absence does not exclude a stone, infection, or another cause of flank pain.
Does pain that changes with movement mean my kidneys are fine?
No. Movement-related pain often suggests a muscle or joint problem, but overlapping symptoms make assessment important when the cause is unclear or warning signs appear.
For support understanding general health information and organizing questions for your clinician, book a health education consultation.
