The costovertebral angle (CVA) is located on your back at the bottom of your ribcage at the 12th rib. It’s the 90-degree angle formed between the curve of that rib and your spine.

“Costo” comes from the Latin word for rib, and “vertebra” comes from the Latin word for joint.

Your kidneys are located behind the CVA on each side. Pain in this flank area may indicate a kidney infection, a back problem, or another kind of internal problem. It’s best to see a doctor when you have tenderness or pain in this area.

Use this interactive 3-D diagram to explore the location of the costovertebral angle:

Pain or tenderness in this area can be caused by many things. The type of CVA pain and symptoms you have may indicate the cause of the pain. Here are some possible causes:

Kidney infection

The kidneys are a likely cause of CVA pain because of their location. Kidney pain may be on one or both sides. If your CVA pain is accompanied by fever or chills and pus or blood in your urine, you may have an infection.

Pyelonephritis, or kidney infection, is fairly common. It affects 15 in 10,000 females and 3 in 10,000 males. More than 250,000 cases are diagnosed yearly. The cause of infection is usually bacterial, coming from the lower urinary tract. In 70 to 95 percent of cases, the bacteria are E. coli.

Pyelonephritis is one of the most common serious infections of young women. If not adequately treated, kidney infections can be life-threatening.

Pyelonephritis is also a common serious complication of pregnancy, affecting 1 to 2 percent of pregnant women.

You should see your doctor right away if you experience symptoms of pyelonephritis.

Kidney stones

When minerals and salt clump together in your kidneys, they can form stones. Stones may not be painful if they’re small. But larger kidney stones can be very painful as they move through your urinary tract. Obesity and diabetes are risk factors for kidney stone formation.

Kidney stones are a common problem. A 2012 national assessment found that kidney stones affect about 1 in 11 people in the United States. More men than women are affected.

If you have a sharp pain in the CVA region, you may have a large kidney stone. Other symptoms of kidney stones are:

  • pain in your lower abdomen
  • pain while urinating
  • blood in your urine
  • nausea and vomiting
  • chills or fever

Polycystic kidney disease

Polycystic kidney disease is inherited but its symptoms aren’t usually noticed until between ages 30 and 50.

This disease causes fluid-filled cysts to damage your kidney tissue and enlarge the kidneys. Eventually this can lead to kidney failure or end-stage renal disease.

Pain in the CVA region can be an early symptom. Other symptoms include:

  • abdominal pain or tenderness
  • blood in your urine
  • frequent urination
  • skin that bruises easily
  • fatigue

Urinary tract infection

Urinary tract infection (UTI) is a very common bacterial infection. According to a 2015 study, UTI symptoms were responsible for an estimated 10.5 million U.S. doctor office visits in 2007, costing the economy $3.5 billion a year in healthcare costs and work time missed.

UTI symptoms depend on where the infection is located. Tenderness and pain in the CVA area is one symptom of an upper tract UTI. This can affect your kidneys. Other symptoms include:

  • chills and fever
  • nausea and vomiting

Lower-tract UTIs affect the urethra and bladder. Symptoms include:

  • increased frequency and urgency of urination
  • bloody or cloudy urine
  • burning with urination
  • pelvic or rectal pain

Urinary tract obstruction

Urinary tract obstruction is a partial or total block of the normal flow of urine through the kidneys, bladder, or urethra. It’s fairly prevalent, ranging from 5 in 10,000 people to 5 in 1,000, depending on the cause.

The obstruction can be structural in children, caused by a birth defect. In young adults it’s usually caused by a stone in the kidney or urinary tract. In older people, causes include:

  • tumors
  • prostate enlargement
  • prostate cancer
  • stones

Symptoms vary depending on the type of obstruction. Pain and tenderness in the CVA area is one symptom. Others include:

  • nausea and vomiting
  • changes in urination

Costochondritis

Costochondritis is an inflammation of cartilage connecting a rib to your breastbone. The pain can vary from mild to severe. Sometimes the pain can mimic that of a heart condition. It may also cause pain in the CVA area.

The exact cause of costochondritis isn’t always known. It may result from trauma, strain, or a virus. This pain goes away over time.

Other causes

There are other possible causes of CVA pain including:

See a doctor if you have CVA pain or tenderness. It’s important to find the cause of the pain and to treat it.

A standard assessment your doctor may perform for CVA tenderness is placing one hand flat on the CVA area and thumping their flat hand with their other fist. This is to allow the kidney to vibrate. You can be standing, sitting, or lying down when your doctor does this. If you don’t feel any pain when your doctor does this, kidney involvement can be ruled out. Here’s a video that shows the assessment.

Along with CVA assessment, your doctor will take your medical history and ask you about your symptoms. Questions might include:

  • When did they begin?
  • How long do they last?
  • Does anything make them better?

They’ll physically examine you and likely order several tests to confirm what’s causing your pain. The tests may include:

You may have other tests, depending on your particular symptoms and what your doctor suspects as a cause.

The risk factors for CVA tenderness and pain vary, depending on the initial cause of the pain. Your risk is related to the initial condition. For example, if you have recurring UTIs, especially those involving the upper urinary tract, you have a greater risk for CVA pain and tenderness recurring.

Other factors that may increase your risk are:

  • kidney stones
  • family history of kidney stones or UTIs
  • diabetes
  • family history of kidney disease, heart attack, or stroke
  • pregnancy
  • sexual intercourse three or more times a week
  • stress incontinence
  • recent spermicide use
  • trauma

Your treatment will depend on the cause of your CVA pain. If the cause is recurrent, you may be referred to a specialist.

Kidney infection

If you have a kidney infection, you’ll be prescribed antibiotics. Your infection should clear up in 48 to 72 hours.

If the infection is severe or if you’re pregnant, you may be hospitalized for treatment.

Kidney stones

Treatment for kidney stones depends on their severity. For small stones, your doctor may recommend pain drugs and tell you to drink a lot of fluids to help flush the stones out.

For larger stones, the doctor may use lithotripsy. This involves the use of shock waves to break up the stone into smaller pieces that can pass out through your urine.

Another possible treatment is ureteroscopy. In this treatment, the doctor uses a tool to find the stone and break it up into smaller pieces. Or, if it’s small, the doctor may remove it.

You’ll have general anesthesia for the lithotripsy or ureteroscopy procedure.

UTIs

Antibiotics are prescribed for UTIs, specific to the bacteria involved. Antibiotic resistance may be a problem. New therapies are under development to address this problem.

When you have pain or tenderness in the CVA area, you should see your doctor. It’s important to find out what’s causing the pain and to treat that condition.

CVA pain is often the sign of a kidney problem such as kidney stones or an infection. It could also be a UTI. In all these cases, early treatment can help avoid complications.