Flank pain is a common but distressing symptom that may affect any individual and heralds a vast array of pathologies. Knowledge about the aetiology and symptomatology of flank pain enables its correct management and treatment. Thus, this blog investigates the varying features of flank pain, offering a comprehensive guide to readers who have or would like to gain more insight into this condition.

What is Flank Pain?

Flank pain is an ache in the right or left zone of the lower back just below the rib cage and above the hip. It is an area where essential organs such as the kidneys and parts of the urinary system are located; therefore, flank pain is likely to relate to diseases or health conditions that affect these organs. Pain can vary from dull and aching to sharp and intense, with other symptoms presented according to the cause.

Flank Pain Causes

1. Renal Stones

One of the most common causes of flank pain is kidney stones. Kidney stones are solid mineral and salt masses that cause excruciating pain as they travel through the urinary tract. The pain is typically sharp in onset and might be felt in waves, radiating to the lower abdomen and groin. The other possible features include blood in the urine, frequent urination, and nausea. 2. Urinary Tract Infections (UTIs)

2. UTIs

UTIs can also cause pain in the flank when the condition extends to the kidneys, a condition referred to as pyelonephritis. Symptoms of UTIs include a persistent urge to urinate, a burning sensation during urination, cloudy or strong-smelling urine, and fever. This pain is confirmed by further aggravation, particularly when the infection reaches the level of the kidneys.

3. Muscle Strain

Common causes of flank pain include muscle strain or injury. It is mainly due to overuse, heavy lifting, or sudden movement that exerts extra pressure on the lower back muscles. The patient usually experiences this kind of pain localised in that part of the body and with aggravation during movement or physical exertion. Muscle strain is mainly presented with stiffness and limited range of motion.

4. Renal Infection

Another essential cause, some of which require urgent medical help, is pyelonephritis, which is most frequently an extension of UTIs into the kidneys. Classically, it is a triad: severe pain in the flank, fever, and sometimes chills with nausea and vomiting. Without therapy, the infection can cause conditions like renal damage and even sepsis.

5. Shingles

Shingles are the varicella-zoster virus reactivation and may result in pain in the flanks if the nerve pathways affected are those in the lower back. The pain involved with shingles is generally described as burning or tingling and is associated with a red rash that usually has blisters. Pain from shingles can be severe, sometimes lasting beyond the healing of the rash, which is called postherpetic neuralgia.

6. Gastrointestinal Issues

Some of the gastrointestinal conditions that cause referred pain to the flank area are irritable bowel syndrome, inflammatory bowel disease, or gallstones. Symptoms like abdominal pain, changes in bowel habits, bloating, and digestive disturbances are usually associated with the pain felt from the flank area.

7. Spine Issues

Back and flank pain can also stem from spinal conditions like herniated discs, spinal stenosis, or vertebral fractures. In many instances, these conditions lead to the compression or irritation of the nerves, commonly manifesting pain projected or felt in the flank region. Other common symptoms associated with these conditions include back pain, numbness, or weakness of the legs.

Symptoms associated with Pain in the Flank

Flank pain may be associated with widely varying symptoms depending on the cause. The general symptoms present in these cases may be:

Pain Quality: It can be sharp, dull, aching, or burning; continuous or intermittent; and may radiate to other places such as the abdomen, groin, or back.
Urinary Symptoms: This includes the need to pee very often, a burning sensation or stinging feeling while peeing, blood in the urine, and changes in the colour or a strange smell of urine.
Digestive Symptoms: Nausea, vomiting, diarrhoea, constipation, and abdominal bloating.
Systemic Symptoms: Signs such as fever, chills, fatigue, general ill-feeling, and the like often indicate an infection and inflammatory process.
Neurological Symptoms: Numbness, tingling, or weakness of the lower extremities indicate nerve involvement or spinal complaints.

Diagnosis of Flank Pain

The basis for establishing flank pain would be a medical assessment that incorporates the history and physical examination according to the patient, diagnostic procedures, and testing.

Medical History - It helps to gain a proper medical history concerning the causes of flank pain. The healthcare provider will question the patient about the pain's occurrence, duration, intensity, and nature and associated symptoms. Information regarding recent trauma, infectious diseases, and other comorbid diseases would be significant.

Physical Examination - The abdomen, back, and flanks are observed closely for local signs of tenderness, bulging, or other possible abnormalities. Tender palpation is performed to assess the presence of muscle strain or any pathology involving the spine. Moreover, any presence of infection or inflammation will be discerned.

Tests in a laboratory - One can also diagnose it from kidney infections and systemic conditions, among others. Blood tests show infection and inflammation signs or indications that the kidney is not working correctly; urine samples could also indicate bacteria, blood, or crystals.

Imaging Studies - These may include ultrasound, X-rays, CT scans, and MRI, each of which can show internal organs and structures. These tests can detect kidney stones, tumours, infections, and spinal abnormalities, which can cause flank pain.

Special Tests - These may include specialised tests like cystoscopy, intravenous pyelogram, or urodynamic studies. These tests help to provide more information about the functioning and structure of the urinary system.

Conclusion

Conditions ranging from minor ones, such as muscle strains, to major ones, including severe infections or kidney problems, can produce flank pain. Management and successful treatment are best achieved by the early recognition of possible causes and other symptoms, along with modes of diagnosis. Immediate medical care is equally necessary for the identification of a proper diagnosis with the attendant treatment of persistent or severe pain on the side. Early diagnosis and intervention can prevent complications and ensure better health outcomes.

References

https://my.clevelandclinic.org/health/symptoms/21541-flank-pain
https://www.mountsinai.org/health-library/symptoms/flank-pain