Flank is the area between the last rib and the hip are found, i.e. the side of the body.
It is a pain or discomfort felt on one side of the body between the upper belly area or abdomen and the back. It develops in the area below the ribs and above the pelvis.
The pain is normally worse on one side of the body.
The discomfort caused by flank pain is usually temporary but feeling the discomfort constantly and having severe pains may mean something else such as a serious medical condition like urinary tract infection or dehydration. Kidney problems such as kidney problems can also cause persistent flank pain. Flank pain is usually a sign of a kidney problem but because there are a lot of other organs in the area, there might be other possible causes. A flank pain coupled with chills, fever, urgent or frequent urination, and blood in the urine means that a kidney problem is likely the cause of flank pain. It may be a sign of kidney stones. The character of the flank pain can help in determining the cause of it. Significant characteristics of flank pain include severity of pain, duration, acute or chronic or recurrent pain, or local or referred pain.
Flank pain is usually linked with less precise symptoms that include vomiting and nausea, fever, and tachycardia. Having a fever indicates an infection nearest the ureteral obstruction. A precise and quick diagnosis of ureteral obstruction and relief of the obstruction is required for flank pain accompanied by fever because infection close to the obstruction results in more rapid damage to the kidneys that occurs with obstruction without infection. The patient might also be inclined to septicemia in the presence of infection close to a ureteral obstruction.
The severity and the location of the flank pain normally rely on the underlying condition and ranges from acute to moderate and typically gets worse with some movement, e.g. a left flank pain suggests a pain occurring in the left kidney while a right flank pain may be a result of a problem occurring in the right kidney. There are times that a minor condition may result in a fair amount of pain in the flank area that might get worse with increased movements of the body.
Acute flank pain may be excruciating, without any changes in the level of pain with movements. The pain in the flank area can travel in a downward direction causing labial pain and testicular pain. Treatment may vary depending on the underlying cause and these may include drinking lot of fluids, rest, exercise, physical therapy, analgesics, antibiotics and anti-inflammatory drugs.
Causes of Flank Pain
Here are some of the possible causes of flank pain:
- Kidney stones
- Kidney infection
- Kidney/renal abscess
- Shingles (pain in a one-sided rash)
- Bladder infection
- Tietze’s syndrome
- Spinal fracture
- Muscle spasm
- Pinched nerve in the back
- Disc disease
- Physical injury
- Muscle strain
- Gallbladder problems
- Gastrointestinal disease
- Back problem like disk disease
- Liver disease
- Musculoskeletal contusion
- Musculoskeletal strain
- Pinched Nerve
- Rib pain
- Local infection
- Bladder outlet obstruction
Here are the less common causes of flank pain:
- Kidney disease
- Polycystic kidney disease
- Inflammatory bowel disease like Crohn’s disease
- Herpes zoster
- Blockage of the urinary tract
- Renal infarct that occurs when a blood clot blocks the blood supply to the kidney
- Abdominal aortic aneurysm
- Kidney/renal tumor or cancer
- Bladder cancer
- Kidney/renal infarction
- Hemorrhage of the kidney
- Renal vein thrombosis
- Dermatologic conditions
- Compression from local growth of a mass
- Neurologic conditions
- Referred pain from thoracic pathologies
- Neuropathic pain
- Pleural pain
- Venous obstruction
- Stricture disease
- Extrinsic compression
- Intraluminal obstruction
Most Common Causes of Flank Pain with the Symptoms Associated with them.
Symptoms of Kidney Problems or Urinary Tract Infection (UTI)
Kidney stones may result in sudden and serious flank pain that might come in waves.
The pain may also reach the groin area. The pain increases and continues while the stone navigates through the bladder, ureters, and out the urethra.
Pain experienced in the lower abdomen or back may be caused by a lower UTI just like an infection in the bladder. Pain experienced in the upper kidney area or back may be due to an upper UTI.
Other symptoms of kidney problems or UTI accompanied by flank pain might include:
- Pain or burning sensation while urinating
- Blood in the urine
- Frequent urge to urinate
Symptoms of Dehydration:
Flank pain that is accompanied by the following symptoms may mean dehydration and you should seek immediate medical attention:
- Extreme thirst
- A fast pulse
- A lack sweat output
- A dry and sticky mouth
- Dark urine
- Decreased urine output
Symptoms of Musculoskeletal Problems:
Flank pain can also be due to musculoskeletal problems such as muscle tear or strain because of a trauma or fall, increased physical activity, repetitive motion, and lifting something too heavy. Flank pain may also be due to a pinched nerve or spinal arthritis.
A pain that is muscle-related will feel more of a shallow ache that gets worse with pressure, physical activity, or any action that use those muscles such as laughing or sneezing.
Diagnosing the Cause of Flank Pain
To identify the underlying cause of a particular flank pain, the doctor may ask the following questions:
- Where is the pain located?
- When did the pain begin?
- What does the pain feel like? Sharp, aching, or dull?
- How often do you experience the pain? Is the pain always there or does it come and go?
- How long do you experience the pain?
- Does the pain get worse?
- What other symptoms do you have?
The underlying cause of flank pain can also be diagnosed through blood tests and imaging tests such as chest x-ray, lumbosacral x-ray, abdominal or kidney ultrasounds. These imaging tests can show issues in the muscles, tissues, and organs while the blood tests can check liver and kidney function.
The other diagnostic tests that may be recommended are:
- Urine culture – detects bacteria in urine
- Urinalysis – can detect disorders such as urinary tract infection
- Cystoscopy – a minor procedure that allows the doctor to examine the lining of the bladder and the tube that carries urine out of the body
- Abdominal CT scan – a type of a specialized x-ray that can show cross-sectional images of the abdomen
- Intravenous pyelography (IVP)
- Retrograde ureteropyelography
- Voiding cystourethrography
Treatment of Flank Pain
Any kind of flank pain is treated by resting as rest is the primary treatment for any kind of flank pain. The minor kinds of flank pain can be treated with physical therapy and rest. Specific exercises can also be recommended to relieve the body from muscle spasms.
Treatment of Urinary Tract Infection:
UTI is treated with antibiotics prescribed by the doctor which is usually taken for a week. Symptoms normally clear up a couple of days after taking the antibiotics. Severe or recurring UTIs might lead to a more severe condition so the doctor may refer you to a urologist.
Treatment for Kidney Stones:
Drinking lots of water and taking pain medications are recommended by the doctor until the small stones pass through urination. Coconut juice and cranberry juice can also help in letting the stones out of the body. There are also medications that can help let the stones out of the body in case one has trouble in letting the stones pass on their own.
Larger stones that do not fit the urinary tract can be removed by lithotripsy or surgery. Lithotripsy is a procedure that involves using high-frequency sound waves to break down large kidney stones into small pieces to let them out of the body.
The doctor may also recommend you to take prescription drugs and stay at the hospital depending on the level of pain.
Treatment for Musculoskeletal Problems:
Muscle-related pains can be treated with non-steroidal anti-inflammatory drugs such as ibuprofen. Putting ice on the area that where you feel the pain for about 20 minutes at a time can also relieve the pain.
Treatment of Flank Pain Caused by Inflammation:
Flank pain that is caused by inflammation coupled with arthritis and infections can be treated according to the specific condition.
For kidney infections, a doctor may require hospitalization to let the antibiotics pass through your veins.
Pain caused by arthritis in the spine can be treated by exercise programs and physical therapy. The doctor may also prescribe anti-inflammatory medicines to reduce discomfort and inflammation. In some occasions, people may need surgery to correct a spinal problem.
Prevention of Flank Pain
Flank pain can be prevented by:
- Keeping yourself hydrated and drinking at least eight glasses of water a day
- Having a healthy diet that consists of fruits, vegetables, and lean proteins
- Limiting the amount of alcohol intake
- Doing proper exercise at least three times a week
- Having a proper hygiene
- Practicing safe sex
When to See a Doctor About a Flank Pain
You should see a doctor immediately if you are experiencing the following signs:
- Constant pain in one side of the flank or back
- Urinary tract infection (UTI)
- fatigue, body aches, high fever, and chills
- vomiting and nausea
- Red or brown blood in the urine