What is a Flank Hernia? Definition, Causes, Symptoms, and Treatment

September 30, 2025 •

4 min read

While hernias are relatively common, affecting millions of people, a flank hernia is a rare and distinct type, also known as a lumbar hernia. It develops from a defect in the posterolateral abdominal wall, the area on the side and back of the abdomen between the lowest rib and the hip bone. Early identification is key to a successful treatment outcome.

Quick Summary

A flank hernia is a rare type of hernia occurring through a weakness in the side or back abdominal wall. Symptoms include a side bulge, pain, and a pulling sensation. Causes are often trauma or prior surgery, with surgical repair being the standard treatment.

Key Points

Definition: A flank hernia, or lumbar hernia, is a rare type of hernia where abdominal contents protrude through a weak spot in the muscle on the side and back of the abdomen.
Causes: Common causes include blunt force trauma to the side, prior surgical incisions in the abdominal wall, congenital defects, and repetitive strenuous activity.
Symptoms: A bulge on the side or back of the abdomen, pain, and a dragging or pulling sensation are common signs.
Diagnosis: In addition to a physical exam, a CT scan is the gold standard for diagnosing a flank hernia and assessing its location.
Treatment: Surgical repair is the standard treatment and can be performed via open, laparoscopic, or robotic-assisted techniques, often involving the use of mesh.
Recovery: Recovery involves avoiding strenuous activity and heavy lifting for several weeks to prevent recurrence.
Prevention: Maintaining a healthy weight, practicing proper lifting techniques, and managing chronic coughing or constipation can help reduce risk.

A flank hernia, or lumbar hernia, is a defect in the side and back of the abdominal wall, a location that distinguishes it from more common hernias like inguinal or umbilical types. While other hernias tend to occur in areas with natural openings, a flank hernia results from a weak spot in the posterolateral muscles and fascia. This weak spot allows abdominal tissue to protrude, creating a visible bulge. Though relatively uncommon, these hernias often require specialized surgical care due to their complex anatomical position.

Causes of Flank Hernias

Unlike many hernias caused by general straining, flank hernias are frequently linked to specific events or pre-existing conditions that compromise the structural integrity of the side and back abdominal wall. Common causes include:

Blunt Force Trauma: A direct, forceful injury to the side of the abdomen or back can damage the muscle and connective tissue, leading to a defect.
Prior Surgery: Surgical incisions in the flank or upper abdomen, such as for kidney, spine, or liver surgery, can weaken the abdominal muscles. If the tissue does not heal completely, a gap may form, resulting in an incisional flank hernia.
Congenital Defects: Some individuals are born with a weakness in the abdominal muscles that can predispose them to developing a hernia later in life.
Repetitive Strenuous Activity: Activities that involve repeated or heavy straining, though not the primary cause, can contribute to the development or worsening of a hernia in a weakened area.

Symptoms and Diagnosis

Recognizing the signs of a flank hernia is the first step toward treatment. While some small hernias may be asymptomatic, more pronounced ones present with noticeable symptoms.

Common Symptoms

A bulge: A lump or protrusion on the side or back of the abdomen is a hallmark symptom. The bulge may become more apparent when coughing, standing, or straining.
Pain: Discomfort or pain in the side or back, particularly in the area of the bulge, which may worsen with activity.
Dragging or Pulling Sensation: A persistent feeling of heaviness or pulling in the flank area.

Diagnostic Techniques

After a physical exam, a doctor may use imaging to confirm the diagnosis and assess the hernia's size and contents.

Computed Tomography (CT) Scan: Considered the gold standard for diagnosing flank hernias, a CT scan provides detailed images of the abdominal wall and can identify defects and their precise location.
Ultrasound: Can be used as a supplementary tool to visualize the abdominal wall and the hernia defect.
Magnetic Resonance Imaging (MRI): Sometimes used to detect a tear in the abdominal muscles, especially if symptoms are present but no visible bulge exists.

Treatment Options

Surgery is the only definitive treatment for a flank hernia, as they do not heal on their own and tend to worsen over time. Surgical approaches vary based on the hernia's size, location, and the patient's overall health.

Surgical Approaches for Flank Hernia Repair


Surgical Method	Description	Advantages	Considerations
Open Hernia Repair	A single incision is made near the hernia, allowing the surgeon to push the protruding tissue back and reinforce the weak spot, often with mesh.	Offers direct access for complex repairs and larger defects. Can provide more stable mesh placement for better long-term results.	Can require a longer hospital stay and recovery period compared to minimally invasive options.
Laparoscopic Hernia Repair	Multiple small incisions are made, and a camera and specialized tools are used to repair the hernia from inside the abdomen.	Associated with smaller scars, less pain, and faster recovery times.	May be challenging for hernias located deep in the flank area due to the anatomical position.
Robotic Hernia Repair	Similar to laparoscopic surgery, but a robotic system enhances the surgeon's precision and dexterity.	Increases surgical precision for a potentially superior repair.	Availability and specific techniques can vary by institution and surgeon expertise.

Complications and Recovery

If left untreated, a flank hernia can lead to incarceration, where the protruding tissue gets trapped, or strangulation, where the blood supply is cut off—both are medical emergencies. After surgical repair, patients typically spend a few days in the hospital, especially for complex cases. Recovery involves gradual return to activity, with restrictions on heavy lifting for several weeks to prevent recurrence.

Life After Flank Hernia Surgery

Initial Recovery (Days to weeks): Patients will experience some pain and discomfort, which can be managed with medication. An abdominal binder may be recommended for support.
Activity Restrictions: Strenuous activities and heavy lifting are restricted for several weeks to allow the repair to heal fully.
Long-Term Outlook: While surgery is generally successful, recurrence is possible, emphasizing the importance of proper recovery and avoiding excessive abdominal strain.

Prevention

While some risk factors are unavoidable, individuals can take steps to minimize their risk of developing a flank hernia or prevent recurrence:

Maintain a Healthy Weight: Excess weight places additional pressure on the abdominal wall.
Lift Safely: Use proper form when lifting heavy objects, bending at the knees instead of the waist.
Prevent Constipation: Consume a high-fiber diet and stay hydrated to avoid straining during bowel movements.
Quit Smoking: Smoking can lead to a chronic cough, which puts repetitive strain on abdominal muscles.
Manage Chronic Conditions: Seek treatment for conditions like chronic coughing or persistent allergies that cause coughing.

Conclusion

A flank hernia is a unique and relatively rare type of hernia occurring through a defect in the side or back abdominal wall. Often caused by trauma or previous surgery, it presents as a painful or heavy-feeling bulge and typically requires surgical repair. Given its complex anatomical location, it is crucial to seek specialized medical care if you suspect you have a flank hernia. Prompt diagnosis through imaging like CT scans and appropriate surgical intervention are essential for a good prognosis and for preventing serious complications like incarceration or strangulation. Long-term prevention focuses on lifestyle modifications to minimize abdominal wall strain.

Frequently Asked Questions

A flank hernia may feel like a lump or bulge on the side or back of your abdomen. It can also cause a dragging or pulling sensation, or pain that gets worse when you cough, stand, or strain.

While most flank hernias are not initially dangerous, they can lead to serious complications if left untreated. These include incarceration, where the tissue becomes trapped, or strangulation, which cuts off blood supply and is a medical emergency.

A flank hernia will not heal on its own and will likely grow larger over time. While small, asymptomatic hernias can sometimes be monitored with a "watchful waiting" approach, most will eventually require surgery to prevent complications and recurrence.

A doctor can check for a flank hernia with a physical examination, often asking you to cough or strain to make the bulge more prominent. Imaging tests like a CT scan, MRI, or ultrasound are used for confirmation.

An inguinal hernia occurs in the groin area and is the most common type of hernia. A flank hernia is much rarer and develops on the side or back of the abdomen, specifically in the posterolateral abdominal wall.

Heavy lifting can contribute to a flank hernia, especially if the abdominal wall is already weakened. However, flank hernias are more commonly caused by specific trauma or prior surgery, unlike inguinal hernias, which are frequently caused by general strenuous activity.

Recovery time varies based on the complexity of the surgery, but a typical recovery is about 2 to 4 weeks. Strenuous activity and heavy lifting are usually restricted for a longer period, often 6 to 8 weeks, to ensure proper healing.