What Is a Femoral Hernia and When Is It an Emergency?

A femoral hernia is a bulge of tissue, usually a loop of intestine or fatty tissue, that pushes through a weak spot in the groin just below the crease where your leg meets your abdomen. It sits in a narrow channel called the femoral canal, which normally contains only fat, lymph nodes, and blood vessels. Because that channel is tight and rigid, anything that slips into it has trouble slipping back out, and that makes femoral hernias more prone to becoming trapped than other groin hernias. When tissue gets stuck and its blood supply is cut off, the situation becomes a surgical emergency that can turn life-threatening within hours.

How a Femoral Hernia Differs from Other Groin Hernias

Most groin hernias are inguinal hernias, which push through a gap higher up in the groin. Femoral hernias take a different path, emerging through the femoral canal, a space that runs alongside the major blood vessels supplying the leg. The opening is bordered by stiff structures, including a tough ligament along its front edge and the femoral vein on its outer side. That anatomy matters because it explains why femoral hernias are so dangerous: once tissue enters the canal, the rigid walls act like a snare, making it difficult for the tissue to slide back to where it came from.

Femoral hernias account for a small fraction of all groin hernias. In one large analysis, they made up about 2.8 percent of initial groin hernias overall, but roughly 19 percent of groin hernias in women.¹ In a single-institution study of women with groin hernias, about 35 percent had a femoral hernia, making it the second most common type after indirect inguinal hernias.² Men get them too, but the condition is far more common in women.

Who Is Most at Risk

The single biggest risk factor is being female. The female pelvis is wider, and the femoral canal tends to be slightly larger, leaving more room for tissue to herniate. Pregnancy adds to the risk because it stretches the abdominal wall and repeatedly raises pressure inside the abdomen.³ Age is the other major factor. In women, the rate of groin hernias rises steeply with age, going from about 15 per 100,000 person-years in 18-to-29-year-olds to roughly 148 per 100,000 in those aged 80 to 89.⁴ That sharp climb reflects the gradual weakening of connective tissue and muscle that comes with aging.

Conditions that chronically raise abdominal pressure also contribute. Chronic obstructive pulmonary disease (COPD) is a recognized risk factor because the persistent coughing it causes repeatedly forces pressure downward toward the groin. Liver cirrhosis with fluid accumulation in the belly, chronic constipation, and smoking are linked to femoral hernias for similar reasons.³

What a Femoral Hernia Feels Like

Many femoral hernias produce surprisingly little in the way of symptoms, at least at first. The most common complaints are vague groin pain and a small lump that appears in the upper inner thigh, just below the groin crease. Among women evaluated for groin hernias at one center, about 74 percent reported non-specific groin pain and roughly half noticed an intermittent bulge. Forty percent had been dealing with symptoms for more than a year before they saw a surgeon.²

The lump can be easy to miss. In thin people it may look like a small grape-sized swelling. In people with more body fat it may not be visible at all and can only be felt on close examination. The bulge sometimes appears when you stand or strain and disappears when you lie down, which can make it seem harmless. But that intermittent quality is deceptive: each time tissue pops in and out of the canal, it risks getting stuck.

When a Femoral Hernia Becomes an Emergency

The emergency arises when the hernia becomes incarcerated, meaning the tissue trapped in the femoral canal can no longer be pushed back in. If the blood supply to that trapped tissue is then pinched off, the hernia is strangulated, and the tissue starts to die. Over half of all femoral hernias are already stuck at the time they are first diagnosed: one study found that 56.5 percent of initial femoral hernias were nonreducible when patients arrived for treatment.¹ A population-based study found that nearly 46 percent of all femoral hernia repairs were performed as emergencies.⁵

What makes this particularly dangerous is how fast the situation develops. In that same population study, over 81 percent of patients admitted as emergencies had first reported hernia symptoms to their doctor only in the seven days before they were hospitalized.⁵ Separate research found that about 40 percent of patients with strangulated hernias had noticed the hernia for the first time only days before the emergency.⁶ In other words, many people go from “I just noticed a lump” to “I need emergency surgery” with almost no warning.

The red-flag symptoms that signal an emergency include:

Sudden severe groin pain: the lump becomes tender and hard and will not go back in when you press on it or lie down.
Nausea and vomiting: if a loop of bowel is trapped, you may develop signs of intestinal blockage.
Abdominal bloating and inability to pass gas or stool: these are hallmarks of bowel obstruction.
Fever or skin redness over the lump: these suggest tissue is already losing blood supply or becoming infected.

What Happens If Strangulation Is Not Treated Quickly

When bowel tissue is trapped and starved of blood, it becomes necrotic, meaning it dies. A dead section of intestine can perforate, spilling bacteria and digestive contents into surrounding tissue. In one reported case, a strangulated femoral hernia that went untreated for several days led to perforation, septic shock, and a severe soft-tissue infection spreading into the thigh. The patient required removal of the dead bowel segment along with emergency surgery.⁷

Delays in getting to the hospital directly affect the severity. Patients who developed bowel obstruction from a femoral hernia had waited an average of about 4.5 days from the onset of symptoms before being hospitalized, compared with about 1.6 days for those without obstruction. The hospital stay for the obstructed group averaged about 11 days, compared to just one day for those treated before obstruction set in.⁸ That gap illustrates how much worse things get with each day of delay.

Why Femoral Hernias Are Easy to Misdiagnose

Because femoral hernias are relatively rare and often small, they are frequently confused with other conditions. A lump in the upper inner thigh can look like a swollen lymph node, a lipoma (a benign fatty lump), or even a vein abnormality. Venous aneurysms in the groin, while uncommon, have been repeatedly misdiagnosed as femoral hernias and vice versa.⁹ A femoral hernia can also be mistaken for the far more common inguinal hernia, which changes the surgical approach.

Imaging helps sort this out. CT scans are highly reliable at distinguishing femoral from inguinal hernias: in one study, CT detected 45 of 46 femoral hernias and found that virtually all femoral hernias showed a characteristic pattern of a localized sac compressing the nearby vein, a feature almost never seen in inguinal hernias.¹⁰ Ultrasound is more accessible and cheaper, but less precise. One study reported about 90 percent accuracy when ultrasound findings were confirmed at surgery, while another found sensitivity around 80 percent and specificity around 88 percent.¹¹ Ultrasound is often the first test ordered in a clinic, but if the results are inconclusive and a femoral hernia is suspected, a CT scan is the next step.

How Femoral Hernias Are Repaired

Surgery is the only fix. Unlike some inguinal hernias where a watch-and-wait approach is occasionally reasonable, the high rate of incarceration with femoral hernias means surgeons generally recommend repair as soon as the diagnosis is made, even if you are not in pain. The logic is straightforward: elective repair done on your schedule is far safer than emergency repair done after tissue has become trapped or died.

The two broad surgical strategies are open repair, where the surgeon makes an incision directly over the hernia, and laparoscopic (keyhole) repair, where the work is done through small incisions with a camera. A large review comparing laparoscopic and open techniques for groin hernias found that laparoscopic repair took longer in the operating room and carried a slightly higher risk of rare serious complications, but patients recovered faster and experienced less chronic pain and numbness afterward. Recurrence rates were similar when mesh was used in both approaches.¹²

Whether to use mesh is a question that comes up in every hernia repair, and the evidence for femoral hernias specifically is still evolving. A systematic review and meta-analysis of mesh versus no-mesh repair for femoral hernias found no significant difference in surgical site infection rates between the two approaches.¹³ A separate study found that using a mesh placed behind the abdominal wall did not change the recurrence rate compared to simple suture repair, whether the operation was elective or emergency.¹⁴ The current data suggest that, for femoral hernias, mesh is not always necessary and that skilled suture repair can produce comparable results.

In emergency settings, things get more complicated. When bowel has been compromised and the surgical field is contaminated, surgeons have historically been wary of placing mesh because of infection risk. A Cochrane review of mesh use in emergency groin hernia repair found the evidence very uncertain, with a possible slight increase in 30-day wound infections, and noted that about 7 percent of meshes placed in contaminated fields had to be removed.¹⁵ The decision in an emergency is highly individual, based on what the surgeon finds inside.

Recurrence After Repair

Femoral hernias can come back, and the risk depends heavily on the circumstances of the original surgery. A systematic review of recurrence rates after open femoral hernia repair found that hernias repaired electively recurred at a rate of about 0.7 percent, while those repaired in emergency settings recurred at about 3.7 percent.¹⁶ The gap makes sense: emergency operations are technically harder, the tissue is inflamed or damaged, and conditions are less controlled. This is one more reason why getting a known femoral hernia repaired before it becomes an emergency pays off.

Femoral Hernias in Children

Femoral hernias are rare in children, but they do occur and present a particular diagnostic challenge. Because they are so uncommon in younger patients, they tend to be mistaken for the far more common inguinal hernia. In one pediatric case series spanning ten years, the correct diagnosis was made before surgery in only 42 percent of cases.¹⁷ Another series reported a correct pre-operative diagnosis in 59 percent of children, with several cases discovered only during or after surgery for what was assumed to be an inguinal hernia.¹⁸ A broader review placed the pre-operative misdiagnosis rate at about 35.5 percent.¹⁹

Even in children, girls are more commonly affected. A misdiagnosed femoral hernia is more than a nuisance: if a child undergoes inguinal hernia repair and the actual femoral hernia is missed, the problem persists and may show up again months later, sometimes as an emergency. Surgeons who operate on children with groin lumps are increasingly advised to inspect the femoral canal routinely, even when the clinical picture points to an inguinal hernia.

Femoral Hernias During Pregnancy

Pregnancy raises intra-abdominal pressure and stretches the groin area, both of which could promote hernia formation. Yet groin hernias diagnosed during pregnancy are quite rare. In a cohort study of more than 20,000 pregnant women, only 25 were registered with a groin hernia. None required emergency or elective repair during the pregnancy, all had uncomplicated deliveries, and in 10 women the groin bulge disappeared on its own after delivery.²⁰ If you notice a groin lump during pregnancy, it is worth having it evaluated, but the outlook is reassuring: most can be watched safely and addressed after childbirth if they persist.

Why Early Elective Repair Matters for Older Adults

Femoral hernias disproportionately affect older adults, and that creates a dilemma. Older patients are more likely to have other health conditions that raise surgical risk, which sometimes leads doctors to take a watch-and-wait approach. But the evidence strongly suggests that this caution backfires with femoral hernias. Emergency repair in elderly patients carries substantially greater risks than planned elective surgery, and researchers have concluded that early elective repair is preferable, ideally under local anesthesia to minimize the added strain of general anesthesia.²¹

The typical story is an older woman who notices a lump in her groin but does not think much of it, or whose doctor attributes it to something benign. The lump may come and go for weeks or months. Then one day the tissue gets stuck, bowel obstruction sets in, and what could have been a straightforward outpatient operation becomes a complex emergency with days or weeks of recovery. Among patients who presented as emergencies in one population study, the vast majority had not been seen by a surgeon before that admission, while only about 2 percent of those treated electively showed up with acute symptoms in the week before their surgery.⁵ Getting a femoral hernia on a surgeon’s radar early is, for most patients, the single most important thing you can do to avoid a bad outcome.

1
The American Surgeon™. Femoral Hernias: Analysis of Preoperative Risk Factors and 30-Day Outcomes of Initial Groin Hernias Using ACS-NSQIP
2
PubMed Central. Natural history of groin hernias in women and factors leading to delay in repair: a single-institution study
3
International Journal of Surgery Case Reports. Strangulated femoral hernia with appendicitis: A rare case of De Garengeot’s hernia
4
PubMed Central. Groin Hernias in Women—A Review of the Literature
5
BJS. Population-based study of presentation and adverse outcomes after femoral hernia surgery
6
PubMed. Hernia repair in elderly patients
7
PubMed Central. Strangulated femoral hernia leading to lower extremity necrotizing soft tissue infection
8
PubMed. Bowel obstruction as a serious complication of patients with femoral hernia
9
PubMed Central. Great saphenous vein aneurysm: A differential diagnosis of femoral hernia and review
10
PubMed. Differentiation of femoral versus inguinal hernia: CT findings
11
PubMed. Role of Sonography in Clinically Occult Femoral Hernias
12
Cochrane Database of Systematic Reviews. Laparoscopic techniques versus open techniques for inguinal hernia repair
13
PubMed Central. Mesh Repair Versus No-Mesh Repair for the Management of Acute and Elective Femoral Hernias: A Systematic Review and Meta-Analysis of Perioperative Outcomes
14
PubMed. Minimising recurrence after primary femoral hernia repair; is mesh mandatory?
15
PubMed Central. Mesh versus non-mesh for emergency groin hernia repair
16
PubMed. Recurrence Rates after Primary Femoral Hernia Open Repair a Systematic Review
17
PubMed Central. Femoral Hernia in Children as a Rare Pathology: A Retrospective Case Series
18
PubMed Central. Femoral hernia in children: How to avoid misdiagnosis?
19
PubMed. Femoral hernia in pediatric population: a diagnostic and surgical challenge
20
PubMed. Primary ventral or groin hernia in pregnancy: a cohort study of 20,714 women
21
PubMed. Emergency hernia repairs in elderly patients