Are flank hernias rare? What you need to know about this unusual condition

September 21, 2025 •

4 min read

Though hernias are common, affecting up to 10% of the population, flank hernias are a considerably rarer and more complex type. Unlike the more familiar groin or abdominal hernias, understanding the nature, causes, and treatment of flank hernias is crucial for proper diagnosis and care.

Quick Summary

Flank hernias, also known as lumbar hernias, are indeed a rare type of abdominal wall hernia that requires specialized surgical care, often due to a prior surgery or traumatic injury. They can present as a bulge on the side of the body, potentially causing discomfort and, if left untreated, serious complications.

Key Points

Rarity: Flank hernias are a rare type of abdominal wall hernia, especially compared to common inguinal and umbilical hernias.
Primary Causes: They are most often incisional (from prior surgery) or traumatic in origin, rather than spontaneous.
Symptoms: Common symptoms include a bulge on the side of the body, pain, or a dragging sensation that worsens with strain.
Diagnosis: A physical exam is often the first step, but a CT scan is the gold standard for definitive diagnosis.
Treatment: Surgical repair is necessary, and due to the complex anatomy, it can be more challenging than for other types of hernias.
Surgical Options: Open surgery is often preferred for more complex cases, while laparoscopic or robotic approaches may be used for smaller defects.

Understanding Flank Hernias

Flank hernias, or lumbar hernias, involve the protrusion of abdominal contents through a weakness in the posterolateral abdominal wall. This area, situated between the rib cage and the hip bone, is less commonly affected than the groin or umbilical regions. Their rarity, anatomical complexity, and proximity to nerves and bones contribute to the challenges associated with both diagnosis and treatment.

What are the main causes of flank hernias?

Flank hernias do not typically occur spontaneously. They are most often the result of either trauma or previous surgical procedures.

Prior Surgery (Incisional): Surgeries that involve an incision in the lateral abdominal wall, such as kidney surgery (nephrectomy) or spine surgery, are a common cause. The wound may not heal completely, leaving a weakened spot susceptible to herniation. Estimates suggest that an incisional hernia can occur in up to 17% of patients after a flank incision.
Trauma: Blunt force trauma to the side of the body can create a tear or weakness in the abdominal wall, leading to a hernia. This is a more rare cause but results in a potentially difficult-to-manage problem.
Congenital or Spontaneous Defects: In very rare cases, a flank hernia may be present from birth due to a musculoskeletal defect or develop spontaneously. Risk factors like older age, obesity, repetitive strenuous activity, and poor nutrition can contribute.

Symptoms and diagnosis

Symptoms of a flank hernia can range from unnoticeable in the early stages to quite debilitating. A flank hernia will not heal on its own and tends to worsen over time if left untreated.

Common symptoms include:

A noticeable bulge or lump on the side or back of the abdomen.
Pain or a dragging sensation in the side that may worsen with coughing, straining, or standing.
In more severe or advanced cases, symptoms may include nausea, vomiting, or signs of a bowel obstruction.

Diagnostic process:

Diagnosis is typically based on a physical examination, especially when a noticeable bulge is present. However, imaging tests are crucial for confirmation and to determine the full extent of the hernia, especially given its uncommon nature.

CT Scan: A Computed Tomography (CT) scan is considered the gold standard for diagnosis, as it can clearly show the fascial defect and the herniated contents.
Ultrasound: Ultrasound can be used as an initial screening tool, particularly when a clinical diagnosis is unclear.

Comparison with other hernia types

To highlight the rarity and unique challenges of flank hernias, it is useful to compare them with more common types.


Feature	Flank Hernia (Lumbar Hernia)	Inguinal Hernia	Umbilical Hernia
Location	Posterolateral abdominal wall (side of the body)	Groin region	At or near the belly button (umbilicus)
Rarity	Rare, often incisional or traumatic	Very common, especially in men	Common, particularly in infants and adults after surgery
Surgical Complexity	Complex, due to proximity to bony structures and nerves	Standard, straightforward repair	Routine repair
Primary Cause	Trauma, prior flank surgery	Straining, weakened abdominal muscles	Pregnancy, obesity, prior surgery

Treatment and recovery

Because flank hernias do not resolve on their own, surgical repair is required. The anatomical location presents a technical challenge for surgeons, and different approaches may be used based on the hernia's size and position.

Open Repair: Often recommended for larger or more complex flank hernias, as it allows for better access and more stable mesh placement.
Laparoscopic or Robotic Repair: May be used for smaller defects, though the anatomy can make it difficult to perform with small tools.

Regardless of the technique, the goal is to reinforce the weakened abdominal wall, often using a surgical mesh. Recovery can be more involved than for other hernia types, potentially requiring a few days of hospitalization. Strenuous activity should be avoided for several weeks following surgery.

It is essential to consult a hernia specialist, as an experienced surgeon can help determine the safest and most effective surgical option. For further information on hernias in general, a reputable resource like the NIH provides comprehensive details on various types: Overview: Hernias - InformedHealth.org.

Conclusion

While the answer to are flank hernias rare? is a definitive yes, it is important for individuals with symptoms to seek expert medical care. This rare condition, also known as a lumbar hernia, is typically caused by trauma or prior surgery and requires specialized surgical intervention. Prompt diagnosis, often with the help of a CT scan, can help prevent complications and lead to a more effective treatment plan. Consulting a specialized hernia surgeon is crucial for a successful outcome, highlighting the importance of expertise when dealing with this complex form of abdominal wall hernia.

Frequently Asked Questions

A flank hernia, or lumbar hernia, is a defect in the posterolateral abdominal wall on the side of your body, between the rib cage and hip bone. This defect allows abdominal contents to protrude, creating a bulge.

Flank hernias are significantly rarer than more common types like inguinal (groin) or umbilical hernias. Most flank hernias occur as a result of a prior surgical incision or trauma, rather than spontaneously.

The most common symptom is a visible bulge on the side of the abdomen. Patients may also experience pain or a dragging sensation in the area, particularly when coughing, standing, or straining.

Flank hernias are most often caused by previous surgery on the side or back, or by blunt force trauma to the abdomen. Other factors like obesity, older age, or a congenital defect can also contribute.

No, a flank hernia will not heal by itself. Surgical intervention is required to repair the abdominal wall defect and prevent the hernia from growing larger or causing complications.

Diagnosis begins with a physical exam, but because flank hernias are rare, a CT scan is typically performed to confirm the diagnosis and provide a detailed view of the defect for surgical planning.

The standard treatment is surgical repair. The complexity of the repair depends on the hernia's location and size, and an experienced surgeon may use an open, laparoscopic, or robotic approach, often involving mesh reinforcement.