Flank Pain

What is flank pain?

The flank is the area on the sides and back of your abdomen, between your lower ribs and your hips. Pain in this area is called flank pain. Several injuries, diseases and infections can cause pain in the flanks.

Flank pain can range from mild to severe. The pain can be sharp or a dull ache, and it may come and go. It’s usually worse on one side, but it can occur on both flanks.

Problems in the kidney (such as an infection or a kidney stone) are common causes of flank pain. Back injuries also cause pain that starts in the spine and travels to the flanks. Healthcare providers treat the condition that’s causing flank pain. Treatments include rest and medication.

How common is flank pain?

Flank pain is very common. Nearly everyone gets flank pain at some point.

Kidney stones are one of the most common causes of flank pain. Every year in the United States, more than half a million people receive treatment for kidney stones. One in 10 people will get a kidney stone during their lifetime.

What causes flank pain?

Pain in the flanks can result from several injuries, conditions and diseases. The most common causes of flank pain include:

• Problems in the urinary tract: Severe kidney pain can result from several types of urinary tract infections (UTI), including a kidney infection and infection of the bladder. Infections and ureteral obstructions (like kidney stones) usually cause pain as well as other symptoms, such as fever, chills, bloating, vomiting and blood in the urine (hematuria). Dehydration can lead to urinary tract problems that cause flank pain.
• Back problems: Arthritis, fractures and structural problems in the spine can cause lower back pain. A herniated disk, pinched nerve and degenerative disk disease cause pain to spread to the flanks. Severe strains can lead to muscle spasms in the flank or lower back.
• Disease: Flank pain may be a sign of several types of disease, including gallbladder disease, liver disease, kidney cancer and some gastrointestinal diseases. Renal artery disease, a condition that blocks blood flow to the kidneys, can also cause flank pain.
• Shingles: A viral infection causes shingles. Symptoms of shingles include a painful rash, usually on one side of the trunk (torso).
• Abdominal aortic aneurysm: The lower part of the aorta (the main blood vessel that carries blood away from the heart) can swell up. If it gets too big, it can rupture (tear). An abdominal aortic aneurysm causes pain and tenderness in the flank area.

How will my provider determine the cause of flank pain?

Your provider will examine you and gently feel the sensitive area. They will ask you where you feel pain and if it gets better or worse with certain activities. Tell them about any symptoms you’re having in addition to flank pain.

Your provider may order several tests to look for signs of kidney stones, infection, injuries or disease. These tests include:

• Basic metabolic panel (BMP) to be sure your kidney function remains normal and that there is no obstruction from a kidney stone.
• Complete blood test (CBC) and urine tests, to see how your organs are working, check for infection and detect signs of cancer and other disease.
• CT scan or ultrasound, to look for kidney stones and check their size and shape.
• Cystoscopy, to diagnose problems in the lower urinary tract.
• Spine X-ray or MRI, to see detailed images of injuries or abnormalities in your spine.

How do healthcare providers treat flank pain?

Treatments depend on what’s causing flank pain. Depending on the cause, your provider may recommend:

• Antibiotics: Your provider will prescribe antibiotic medications to treat flank pain that results from an infection. It’s essential to follow your provider’s instructions and take the entire course of antibiotics so the infection doesn’t return.
• Extra water: If a small kidney stone is causing pain, you may be able to pass it by drinking a lot of water. Ask your provider how much you should drink. To remove larger stones, you may need medications or a minimally invasive procedure such as ureteroscopy or shockwave lithotripsy.
• Pain medication: Over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs) relieve pain and help you feel more comfortable as you heal. If pain is severe, you may need prescription drugs. Talk to your provider before taking any medication.
• Rest: Flank pain that results from a back sprain or strain often improves with rest. Ask your provider how long you should rest and when you can get back on your feet. Stretching, exercise and a physical therapy (PT) program can strengthen muscles in your spine and help you avoid another injury.
• Surgery: Some conditions (such as cancer) may require surgery or other treatments. Talk to your provider about the most appropriate treatment plan for you.

How can I prevent flank pain?

You may not always be able to prevent flank pain. But you can reduce your risk of kidney problems, injuries and disease by maintaining good health. You should:

• Eat right and stay hydrated: By drinking plenty of water, avoiding alcohol and eating a healthy diet, you can lower your risk of kidney stones. Water keeps you hydrated and flushes out your kidneys, decreasing the chance of infection and making it more difficult for stones to form. Ask your provider about a low-sodium, calcium-rich diet that may prevent kidney stones.
• Maintain a weight that's healthy for you: Get regular exercise and stay active. People who have overweight or obesity have a higher chance of developing kidney stones. Extra weight also puts pressure on your spine and makes you more vulnerable to injuries that cause flank pain.
• Take care of your urinary tract: To reduce the risk of bacteria entering your urinary tract and causing an infection, always urinate after having sex. Women should wipe from front to back after urinating. Drink plenty of water, and use the bathroom as soon as you feel the urge. Holding urine in your bladder increases your chance of infection.
• Visit your provider: Stay up to date on vaccines (including the shingles vaccine). Schedule regular screenings for cancer and other diseases, and talk to your provider about reducing your risk of kidney problems.

When should I call my doctor about flank pain?

Call your healthcare provider if flank pain:

• Doesn’t go away in about a day, or if it goes away and comes back.
• Is severe or comes on suddenly.
• Makes it difficult for you to do everyday activities.

Flank pain that occurs along with other symptoms could be a sign of a serious health problem. Call your provider right away if you have flank pain and:

• Blood in your urine or pain when urinating.
• Diarrhea, constipation or bloating.
• Fever, chills or dizziness.
• Frequent need to urinate.
• Headaches.
• Nausea or vomiting.
• Skin rash.

A note from Cleveland Clinic

Flank pain is a symptom of several conditions and injuries. Rest, medications and other treatments can relieve pain and help you feel better. Call your provider if you have severe flank pain or it doesn’t get better in about a day. You should see your provider right away if you also have other symptoms, such as a fever or chills. These could be signs of a serious condition. By drinking plenty of water and maintaining a weight that's healthy for you, you can lower your risk of conditions that lead to flank pain.