Kidney pain: Facts, Causes, Diagnosis & Treatments

Picture of Kidney pain


What is Kidney pain?

The kidneys are paired organs located toward the back of your body, partially protected by your lower ribs. Your left kidney is slightly higher than your right. Pain from the kidneys tends to occur in the flanks or in the lower back just under the ribs, although it can extend into the groin and testicles. Pain from muscle strain, arthritis, and some spinal conditions can easily be mistaken for kidney pain.

Kidney pain is caused by infection, inflammation, injury or enlargement of the kidney, or by conditions that block the flow of urine out of the kidney. Pyelonephritis (kidney infection) and kidney stones are the most common causes of kidney pain. Pyelonephritis is often accompanied by other symptoms of urinary tract infection, such as burning with urination, frequent or urgent need to urinate, bloody urine, fever, and nausea with or without vomiting. Kidney stones may also cause bloody urine, fever, and nausea with or without vomiting; however, the pain tends to come and go in waves.

Kidney pain facts

  • The function and purpose of the kidneys are to remove excess fluid and waste products from the body.
  • The kidneys are organs that are located in the upper abdominal area against the back muscles on both the left and right side of the body.
  • Kidney pain and back pain can be difficult to distinguish, but kidney pain is usually deeper and higher in the back located under the ribs while the muscle pain with common back injury tends to be lower in the back.
  • Causes of kidney pain are mainly urinary tract infections and kidney stones. However, there are many other causes of kidney pain, including penetrating and blunt trauma that can result in a “lacerated kidney.”
  • If a woman is pregnant and has kidney pain, she should contact her doctor.

Causes of Kidney pain?

Pain is the main way that our body tells us something is wrong. Pain is one of the commonest reasons that makes someone go to see a doctor for suspected problems with the kidneys or urine.

Possible causes of kidney pain include:

  1. Bleeding in your kidney (hemorrhage)
  2. Blood clots in kidney veins (renal vein thrombosis)
  3. Urinary tract infection (UTI)
  4. Arteriosclerosis / atherosclerosis (hardening of the arteries leading to the kidneys)
  5. Horseshoe kidney, a condition present at birth in which the two kidneys are fused together
  6. Kidney cancer or kidney tumor
  7. Kidney infection (pyelonephritis)
  8. Kidney swelling due to a backup of urine (hydronephrosis)
  9. Polycystic kidney disease

However, it’s possible to have one of these conditions and experience few symptoms, including kidney pain.

Kidney stones cause pain, but it’s not referred to as kidney pain. Kidney stones generally are painless or relatively painless as long as they remain in the kidneys. It’s when the stones move out of the kidneys that pain typically occurs waves of sharp, intense pain, which doctors call renal colic or ureteral colic.

Where is pain felt?

Pain can come from any part of the kidneys and urine drainage system. The next few paragraphs try to describe how pain occurs with various types of kidney problem. Please remember that everyone is different, so that people feel pain in different ways and in different places. Also, peoples’ bodies and minds respond to pain in different ways.

Pain in the back

The kidneys are found in the upper back (the ‘small of the back’, it is often called). Kidney disease can cause pain in this part of the upper back. Pain in this area is common, and often comes from the muscles of the back, or from the spine. Pain from the kidneys is often constant, or can be sharp, like being stabbed. Pain from the muscles or the spine comes on with bending over or with lifting, and may be felt in the middle of the back, rather than on either side over the kidneys.

The commonest causes of kidney pain in the back are infection (an infection in a kidney is called acute pyelonephritis), and kidney stone (which can cause a very, very severe pain that comes on in spasms, and travels down to the groin, and is called renal colic by doctors).

Pain in the groin (or in the testicles)

The body feels pain in unusual ways, and sometimes pain from an internal organ is felt away from the site of the internal organ (the commonest example is pain from the gallbladder, in the tummy, which can be felt on the tip of the shoulder). The kidneys can be a little like this, so that pain in the kidney can be felt all the way from the back down to the groin, or in the testicles in men.

The testicles can also feel painful due to infection (this can be called orchitis or epididymo-orchitis).

The testicles can also enlarge or become painful due to other important conditions. One of these is testicular cancer, and advice should be sought from a doctor if a testicle (or both) is permanently painful, or increases in size.

Pain that gets worse while passing water (or just before passing water)

A stinging pain in the tube (called the urethra) that carries urine out of your body (from the bladder) is a common symptom of urine problems. Infection is the commonest cause of pain that is present while urine is being passed, and might cause intermittent pain or itching in between passing urine.

The commonest cause of pain of this type is urine infection. If an infection is confined to the bladder there may also be urgency to pass urine frequently, and some pain in the front of the tummy, right down at the bottom. This type of infection, in the urine and bladder, is called cystitis. Bugs in the urine that cause infection can also make the urine foul smelling or cloudy.

Tests are available to Diagnose Kidney diseases?

The doctor usually will do a history and physical examination. Initial tests usually consist of a complete blood count (CBC), kidney function (creatinine and BUN), and urine test, and when appropriate, a pregnancy test. A lacerated kidney may be suspected if the person has experienced a traumatic injury to the lower back.

If kidney stones are suspected, a CT exam (renal protocol or noncontrast spiral CT) or renal ultrasound is done; an abdominal X-ray (KUB) may be ordered but has been replaced in general by ultrasound and CT. As patients with kidney stones often need repeat X-ray studies or have repeat episodes of kidney stones, ultrasound with its lack of radiation is a good study to consider. Abdominal/pelvic CTs with contrast or magnetic resonance imaging (MRI) and aortogram may be ordered to further define or differentiate underlying kidney (renal) and nonrenal causes of flank pain. Such studies are routinely performed if a kidney is suspected to be damaged by a traumatic event (auto accident, gunshot wound, or blunt trauma such as from a collision in football or workplace injury).

Painkillers are safe to take?

Some painkillers purchased ‘over the counter’ at the chemists can be used for kidney pain.

Paracetamol is the safest painkiller if you have kidney pain. Do not take above the recommended dosage (one gramme – 1g or 1000mg – of the active ingredient, usually two tablets, four times a day).

If this is not effective, painkilling tablets containing codeine may be used.

If this is still not effective, talk to your doctor about painkillers. Unfortunately it is often difficult to get complete pain relief in people with severe kidney pain.

Some painkillers can be harmful in some people with kidney trouble. Ibuprofen is not generally recommended if there is any degree of kidney failure. Ibuprofen is also sold under the trade names ‘Nurofen’ and ‘Advil’. Only take ibuprofen for kidney pain if its use has been recommended by a doctor.

Treatment for Kidney pain

Kidney pain (flank pain) treatment depends on the underlying cause of the pain. Infections and kidney stones that cause pain are often treated with ibuprofen, ketorolac (Toradol), acetaminophen (Tylenol and others), or occasionally with small amounts of morphine (kidney stones). However, these agents treat pain (pain relief only) and not the underlying cause(s) of pain.

Infections like urinary tract infections (UTIs) and pyelonephritis usually require antibiotic treatments in addition to pain medications. If kidney stones completely block a ureter or are about 6 mm in diameter, they may require urologic surgery. Severe kidney lacerations may also require surgery. Recovery time varies from weeks to months.

Other underlying causes of flank pain may need similar pain management and concurrent treatments. However, patients with known kidney problems (kidney disease) and/or renal function compromise should not be treated with pain medications that are either filtered (removed) through the kidneys and/or may cause further renal damage.