How to Tell Kidney Pain from Back Pain

Any pain in the lower back makes people think of their kidneys first. In fact, most back pain comes from the muscles and spine, while kidney pain has some distinctive features of its own. In this article you will find tips to help you tell kidney pain from back pain, and the warning signs to look out for.

Where are the kidneys, and where is kidney pain felt?

The kidneys sit on either side of the spine, above the waistline and just below the lower ribs. For this reason, kidney pain:

• Is usually felt in the upper side of the back, in the flank,
• Is mostly on one side,
• May spread to the side of the abdomen, the groin and the genital area.

Back pain caused by the muscles or spine, on the other hand, is concentrated lower down, in the middle of the lower back and right next to the spine.

How can kidney pain be told apart from back pain?

Feature	Pain from the kidney	Back pain from the muscles or spine
Location	Below the ribs, in the side (flank)	Lower and middle part of the lower back
Side	Mostly one side	One or both sides
Spread	To the side of the abdomen, the groin, the genital area	To the buttock, the leg
Relation to movement	Changes little with position	Worse with movement, eases with rest
Accompanying symptoms	Nausea, vomiting, fever, blood in the urine, burning	Numbness, tingling or stiffness in the leg

These tips can point you in the right direction, but the definitive distinction is made through examination and tests. In some cases, a slipped disc and a kidney stone can be present in the same person at the same time.

What does kidney stone pain (renal colic) feel like?

Stone pain is the best known kind of kidney pain, and many people describe it as one of the worst pains they have ever experienced. Its typical features are:

• It starts suddenly; it often appears in the early hours of the morning or at rest.
• It comes in waves; it builds up and eases over a few minutes, but may not go away completely.
• The person cannot keep still; they sit down, get up and walk about, but cannot find a comfortable position.
• As the stone moves down the ureter, the pain shifts from the side to the groin, the testicle or the external genital area.
• When the stone approaches the bladder, frequent urination and a feeling of urgency may begin.

With muscular back pain, by contrast, people usually prefer to stay still, because movement makes the pain worse. This difference is a useful clue for telling the two types of pain apart.

What causes kidney pain?

• Kidney or ureteral stones (renal colic): When a stone blocks the urinary tract, it causes severe pain that starts suddenly, comes in waves and leaves the person unable to keep still. Nausea, vomiting and blood in the urine are common. For treatment options, see the kidney stone treatment page.
• Kidney infection (pyelonephritis): Pain in the side comes with a high temperature, shivering, tiredness and often burning when passing urine.
• Ureteropelvic junction obstruction: A narrowing at the point where the kidney joins the ureter. Pain in the side that gets worse, particularly after drinking a lot of fluid, can be typical. For details, see the ureteropelvic junction obstruction page.
• Kidney cysts: Most cause no symptoms; large cysts can cause a dull ache.
• Kidney tumours: These are mostly painless and are often found by chance on scans done for another reason.
• Injury: A blow to the side can affect the kidney.

What other conditions can feel like kidney pain?

Pain in the side and lower back does not only come from the kidneys:

• Muscle strain and a slipped disc
• Diseases of the gallbladder, pancreas and bowel
• Appendicitis (particularly on the right side)
• In women, gynaecological conditions such as an ovarian cyst or ectopic pregnancy
• Shingles (can start with a burning pain before blisters appear on the skin)
• In older people, widening of the main artery in the abdomen (aortic aneurysm)

For this reason, particularly with severe pain that appears for the first time, you need a medical assessment rather than diagnosing yourself.

Which tests are done for kidney pain?

1. Urine test: Shows the presence of blood, infection and crystals.
2. Blood tests: Kidney function and markers of infection are assessed.
3. Ultrasound scan: Involves no radiation; it is the first step in looking for stones and swelling of the kidney (hydronephrosis).
4. Non-contrast CT scan: Shows the size, position and density of the stone in detail.
5. Further imaging if necessary: If a narrowing is suspected, tests such as a renal scan (scintigraphy), which shows how well the kidney drains urine, may be requested.

What can you do at home?

For pain thought to come from the kidney, you can take a painkiller if your doctor has recommended one. However, relying on painkillers for a long time without knowing the cause of the pain is not advisable. People with reduced kidney function should not take certain painkillers without asking their doctor. For people with a history of stones, drinking plenty of fluids may help; but if you have severe pain, vomiting or a fever, you need to be assessed without waiting.

When should you seek emergency care?

Go to the emergency department (A&E) without delay in the following situations:

• If pain in the side comes with fever and shivering (a blocked and infected kidney may need urgent treatment)
• If the pain cannot be controlled with medicines
• If you cannot keep fluids down because of vomiting
• If the amount of urine you pass has dropped noticeably or you cannot pass urine at all
• If you have only one kidney or have had a kidney transplant
• If pain in the side starts during pregnancy
• If very severe back or abdominal pain starts suddenly, particularly in older age, and comes with dizziness or a feeling of fainting

When should you see a urologist?

A urological examination is advisable if you have recurrent pain in the side, have passed a stone before, have blood in your urine, have frequent urinary tract infections, or have pain that gets worse after drinking a lot of fluid. If you see blood in your urine, you may also want to read our article on the causes of blood in the urine.

Op. Dr. Mücahit Kabar sees patients in Bursa (Nilüfer), Turkey, at Özel Medicabil Nilüfer Hastanesi (weekdays 08:30–12:00, +90 444 8 112) and Özel Jimer Hastanesi (weekdays 13:00–17:00, +90 444 45 67). Appointments are booked through the hospitals’ online booking pages or appointment lines. Consultations are held in English or Turkish; the hospitals’ international patient departments can arrange interpreters for other languages. If you are travelling from abroad, you can send your questions and reports by WhatsApp to +90 541 622 54 82 before your visit. See the contact and appointment information for details.