What Is a Double Hernia? Causes, Symptoms & Treatment

A double hernia is a bilateral inguinal hernia, meaning tissue pushes through the abdominal wall on both the left and right sides of the groin. The two hernias may appear at the same time or develop months to years apart, and they can be the same type or different types on each side. Because both groins share the same underlying tissue composition and risk factors, having one inguinal hernia raises the odds of eventually developing one on the opposite side considerably. The condition is common enough that surgeons routinely debate whether to check the other side during a repair, and the answer to that debate shapes how double hernias are treated today.

What Counts as a Double Hernia

The term “double hernia” is informal. In clinical language, it is a bilateral inguinal hernia. Each side has its own defect in the groin, and each can be classified independently. A direct inguinal hernia pushes through a weak spot in the floor of the inguinal canal, while an indirect inguinal hernia follows the natural path that the spermatic cord or round ligament takes through the canal. You can have two direct hernias, two indirect hernias, or one of each. Less commonly, a femoral hernia on one or both sides can be part of the picture.

A large epidemiologic study tracking groin hernia repairs over 14 years found a strong pattern: people who had one type of hernia on one side were much more likely to develop the same type on the other side than a different type. Men who had a direct hernia repaired on one side had roughly four and a half times the risk of needing a direct hernia repair on the opposite side, and women with a direct hernia had about four times the risk. For indirect hernias the clustering was even stronger in women, with nearly seven times the risk of a matching contralateral indirect hernia.¹ That symmetry makes sense once you understand what causes the weakness in the first place.

Why Both Sides Give Way

The short explanation is that the factors weakening the groin on one side are usually systemic, affecting the whole body rather than just one spot. The most important factor is the quality of your connective tissue, specifically your collagen. Studies comparing hernia patients with hernia-free controls consistently find measurable differences in collagen composition. Patients with direct inguinal hernias have been found to have about 19 percent less collagen-related hydroxyproline in the tissue overlying the defect.² In indirect hernias, researchers have measured roughly 24 percent less type I collagen in the relevant fascia layer.²

Type I collagen is the strong, mature structural fiber that gives tissue its tensile strength. Hernia patients tend to have a shifted ratio, with relatively more type III collagen, a thinner and less robust fiber. A case-control study confirmed that hernia patients showed decreased type I-to-III collagen ratios in both their groin tissue and their skin, suggesting the imbalance is body-wide rather than limited to one anatomical region.³ This is exactly why a hernia on the left predicts a hernia on the right: both sides are built from the same collagen.

Other Risk Factors

Collagen quality sets the stage, but everyday forces determine when and whether the tissue actually fails. Family history is one of the strongest predictors, which makes sense given that collagen composition is largely inherited. A case-control study of adult men found that a positive family history of inguinal hernia was a significant risk factor, as was strenuous physical work and straining during urination or defecation.⁴

Interestingly, patients themselves tend to pin the blame on lifting and gym activity. In a prospective survey, over 40 percent of hernia patients believed their hernia was caused by lifting, and about a quarter cited gym activity, while traditional risk factors like chronic cough and constipation were cited by only 4 percent of respondents.⁵ Whether heavy lifting actually causes hernias or merely reveals an underlying weakness remains debated, but the combination of genetically weaker connective tissue and repeated abdominal pressure is the most widely accepted model. Aging, obesity, smoking, and conditions that create chronic straining all compound the risk. Since all of these affect both sides equally, they help explain why bilateral hernias are so common.

Symptoms of a Double Hernia

Each hernia produces its own bulge in the groin, sometimes visible only when you stand, cough, or strain. The bulge may flatten when you lie down. Many people with a single inguinal hernia describe a dull ache or dragging sensation that worsens with activity. With bilateral hernias, you feel these symptoms on both sides, though the two hernias do not always cause equal discomfort. One side may be larger or more symptomatic, while the other stays small and barely noticeable for months or years.

Some double hernias are discovered only because a surgeon takes a look at the opposite side while fixing the one you came in for. A systematic review found that about 15 percent of patients undergoing unilateral inguinal hernia repair have an occult (hidden) hernia on the other side.⁶ That hidden hernia usually has no symptoms at the time of discovery, but about 29 percent of people who have one ultimately need it fixed.⁶

In children, the numbers are even more striking. A study of more than 1,800 pediatric hernia repairs found a contralateral patent (open) internal inguinal ring in 41 percent of cases. Most of these open rings were closed during the procedure to prevent future hernias from developing on that side.⁷

How Double Hernias Are Diagnosed

Most groin hernias are diagnosed with a physical exam alone. A doctor can usually feel the bulge by having you stand and cough while they press on the inguinal canal. When both sides are symptomatic, the diagnosis of a double hernia is straightforward.

Imaging comes into play mainly when the hernia is suspected but cannot be felt, which is called an occult hernia. Ultrasound is the first-line imaging tool for this purpose. One study found 100 percent sensitivity and specificity for ultrasound in diagnosing groin hernias, though the sample was relatively small.⁸ A systematic review and meta-analysis was more cautious, concluding that ultrasound’s sensitivity for occult groin hernias cannot yet be reliably pinned down across studies. However, it confirmed that ultrasound has a high positive predictive value, meaning that when it says a hernia is there, it almost certainly is, and it can reliably distinguish inguinal from femoral hernias.⁹ The accuracy depends heavily on the examiner’s skill.

In practice, whether you need imaging at all for the second hernia depends on the surgical approach. Laparoscopic repair gives the surgeon a direct view of both groins from inside the abdomen, so a hidden contralateral hernia can be spotted during the operation without any separate imaging test.

Fixing Both Sides at Once Versus Separately

This is the question that dominates the surgical literature on bilateral hernias: should you fix both in one operation or stage them into two? The answer has shifted decisively toward doing both at the same time, especially with laparoscopic techniques.

Early concern about simultaneous repair focused on the idea that operating on both groins at once would produce more complications and higher recurrence rates. A study published in the Annals of Surgery directly tested this by comparing outcomes of simultaneous bilateral repair with unilateral repair. Recurrence rates at five and nine years were essentially identical between the groups. Complication rates were also similar for most specific events, with the notable exception of urinary retention, which occurred in about 15 percent of bilateral patients compared with 6 percent of unilateral patients.¹⁰ That study’s conclusion was blunt: simultaneous repair does not increase most complications or recurrence compared to fixing one side at a time.

The case for simultaneous repair has only grown stronger with laparoscopic surgery. An analysis of more than 1,300 simultaneous bilateral laparoscopic repairs found the approach to be safe, comfortable for patients, and cost-effective, without increased morbidity or recurrence risk compared to unilateral repair.¹¹ A separate study of more than 2,800 patients confirmed these findings: when adjusted for the number of hernias repaired, morbidity was about 1.4 percent for bilateral repairs versus 1.9 percent for unilateral repairs, and recurrence rates were similarly low. That study also found that bilateral laparoscopic repair resulted in significantly shorter time away from work than bilateral open repair.¹²

Open Versus Laparoscopic Repair for Double Hernias

For a single hernia, the choice between open and laparoscopic repair is often a toss-up, influenced by surgeon experience and patient preference. For bilateral hernias, laparoscopic repair has a more distinct edge. The same set of small incisions and internal access points serve both sides. In open surgery, each groin needs its own incision, its own dissection, and its own recovery. A comparative study found that open bilateral repair took about 59 minutes on average, while laparoscopic bilateral repair took about 107 minutes, roughly twice as long in the operating room.¹³ But that extra operating time buys a faster recovery and quicker return to normal activity.

From a cost-effectiveness perspective, a randomized study comparing laparoscopic (TAPP) and open (Lichtenstein) bilateral repair found that the laparoscopic procedure cost more upfront — roughly €1,684 versus €1,193 — but generated significantly higher quality-adjusted life years over the following year. At standard willingness-to-pay thresholds, the laparoscopic approach had over a 95 percent probability of being more cost-effective.¹⁴ A study comparing operating room costs in an open bilateral setting found that bilateral repair added about $280 in operating room costs compared with unilateral, while saving the patient a second anesthesia, a second recovery period, and a second round of time off work.¹⁵

Recovery and Long-Term Outcomes

Most people who undergo bilateral hernia repair go home the same day or the next morning. Recovery timelines are similar to unilateral repair: light activity within a few days, return to desk work in one to two weeks, and return to heavy physical activity in four to six weeks, though these ranges vary by individual and surgical technique.

Quality of life generally improves after bilateral repair. A randomized trial comparing Lichtenstein (open mesh) and TAPP (laparoscopic) techniques for bilateral hernias found significant improvements in physical function, emotional well-being, bodily pain, and general health after surgery, regardless of which technique was used.¹⁶

Chronic groin pain remains the most concerning long-term complication. A 10-year follow-up of bilateral and recurrent hernia repairs found an overall higher incidence of chronic pain in the laparoscopic group compared to the open group (15 versus 8 percent), though the severity of pain was lower in the laparoscopic group. Quality of life was meaningfully reduced in patients with chronic pain compared to population norms, and patients under 65 reported poorer physical health than older patients.¹⁷ International guidelines recommend that surgeons identify and preserve all three inguinal nerves during open repair to reduce the risk of chronic pain, and suggest waiting at least a year after the original repair before considering surgical treatment for persistent pain.¹⁸

Recurrence rates with modern mesh repair are low. One series of 220 hernia repairs using a self-gripping mesh reported a recurrence rate of 1.4 percent at a mean follow-up of about 23 months.¹⁹

When Watchful Waiting Makes Sense

Not every hernia needs immediate surgery. If one or both of your hernias cause minimal or no symptoms, watchful waiting is a legitimate option, especially if you have other health conditions that make surgery riskier. A randomized trial of men with minimally symptomatic inguinal hernias found that 23 percent of those assigned to watchful waiting crossed over to surgery within two years, and the complication rate when they eventually did have surgery was no higher than for those who had surgery upfront.²⁰

The long view is less reassuring for the wait-and-see crowd, however. A systematic review found that about half of watchful-waiting patients ended up needing surgery within five years, with pain being the reason in about 65 percent of cases.²¹ Long-term follow-up from a randomized trial found a cumulative 12-year crossover rate of about 64 percent, meaning roughly two-thirds of people who initially chose to wait eventually had surgery. About 4 percent developed incarceration, a potentially dangerous complication where bowel becomes trapped, though all were treated without lasting harm.²²

For bilateral hernias specifically, watchful waiting introduces a practical wrinkle. If you are going to have surgery on one side anyway because it is symptomatic, the incremental risk and cost of fixing the asymptomatic side at the same time is small. Many surgeons will recommend addressing both rather than waiting for the quieter side to become a problem that requires its own separate operation.

Gender Differences in Bilateral Hernias

Inguinal hernias are far more common in men, but women get them too, and the pattern differs. A study comparing sex-based differences found that women had significantly fewer direct hernias (about 13 percent versus 33 percent in men) and significantly more femoral hernias (about 39 percent versus 12 percent in men). The rate of bilateral hernias, however, was similar between sexes.²³ Femoral hernias carry a higher risk of incarceration and strangulation, so a bilateral presentation in a woman may warrant more urgent surgical attention than the same presentation in a man with two direct hernias.

When Groin Hernias Come With Hernias Elsewhere

Some people present with inguinal hernias alongside hernias in other locations, such as an umbilical or ventral hernia along the midline of the abdomen. These multisite hernias raise the question of whether everything can be fixed in one operation. Robotic surgery has expanded the feasibility of combined repairs. A study of multisite hernia treatment with robotic assistance found that single-docking was feasible when a small midline hernia was combined with a unilateral inguinal hernia, while double docking was necessary for patients with larger midline defects or bilateral inguinal hernias.²⁴ The broader trend is toward addressing all defects in a single session when technically possible, sparing patients multiple anesthetic episodes and recovery periods.

The Hidden Hernia Dilemma

One of the more contentious questions in hernia surgery is what to do when a surgeon finds a small, asymptomatic hernia on the opposite side during what was supposed to be a unilateral repair. Laparoscopic surgery makes this discovery easy because the camera provides a view of both groins. A systematic review modeled the decision: for every 1,000 patients undergoing unilateral repair, checking the other side would reveal about 150 with a hidden hernia. Repairing all 150 would mean about 15 developing a postoperative complication and 105 undergoing a repair they may never have needed. On the other hand, leaving those 150 alone would result in roughly 45 eventually needing a separate operation.⁶

There is no universal consensus. Some surgeons fix every occult hernia they find, reasoning that the added risk is minimal and saves a potential second operation. Others prefer to close up and let the patient decide later if the other side becomes symptomatic. Your surgeon’s approach to this question is worth asking about before you go in for a unilateral repair, because if you have the collagen profile and risk factors that produced one hernia, there is a real chance the other side is already on its way.