There are more than a dozen distinct types of hernias, but they all share the same basic problem: an organ or tissue pushes through a weak spot in the muscle or connective tissue that normally holds it in place. Most hernias occur in the abdomen or groin, though they can also develop in the upper thigh, belly button, and diaphragm. Some are extremely common, while others are rare enough that even experienced surgeons encounter them infrequently.
Inguinal Hernias
Inguinal hernias are by far the most common type. They occur in the groin, where the abdominal wall has a natural channel called the inguinal canal. This canal carries blood vessels and, in men, the cord that supports the testicles. Because of that anatomy, inguinal hernias are significantly more common in men.
There are two subtypes. An indirect inguinal hernia enters through the top of the inguinal canal, usually because the opening didn’t fully close during fetal development. This is the type most often seen in infants and younger adults. A direct inguinal hernia pushes straight through the wall of the canal itself, developing over time as abdominal muscles weaken from aging and chronic pressure. Direct hernias are almost exclusively an adult problem.
Both subtypes typically appear as a bulge in the groin that becomes more noticeable when you stand, cough, or strain. The bulge may flatten when you lie down.
Femoral Hernias
Femoral hernias occur just below the groin crease, where the femoral canal allows blood vessels to pass into the upper thigh. They are far less common than inguinal hernias but disproportionately affect women, partly due to the wider shape of the female pelvis. Femoral hernias tend to be small and can be difficult to detect on physical exam alone. They carry a higher risk of becoming trapped (incarcerated) compared to inguinal hernias, which is why surgical repair is typically recommended even when symptoms are mild.
Umbilical Hernias
An umbilical hernia appears at or near the belly button, where the abdominal wall has a natural weak point left over from the umbilical cord. In newborns, these are very common and usually close on their own by age 4 or 5. In adults, umbilical hernias develop when repeated pressure stretches that weak spot open again. Pregnancy, obesity, and fluid buildup in the abdomen are frequent contributors. You’ll notice a soft bulge at the navel that may ache or become more prominent with activity.
Incisional Hernias
Any abdominal surgery leaves a scar in the muscle wall, and that scar tissue is never quite as strong as the original muscle. An incisional hernia pushes through a previous surgical site, sometimes months or even years after the operation. Research has identified unique patterns of gene activity related to inflammation and cell adhesion at these sites, suggesting that some people’s tissues simply don’t heal as robustly. Obesity, diabetes, smoking, and wound infections after the original surgery all raise the risk.
Hiatal Hernias
Hiatal hernias are different from other types because they occur inside the body, at the opening (hiatus) in the diaphragm where the esophagus passes through to meet the stomach. There are four recognized types:
- Type I (sliding): The junction between the esophagus and stomach slides upward through the diaphragm. This is the most common type and the one most closely linked to acid reflux.
- Type II: The upper portion of the stomach bulges up through the hiatus, but the junction between the esophagus and stomach stays in its normal position below the diaphragm.
- Type III: A combination of Types I and II, where both the stomach and the esophageal junction migrate upward.
- Type IV: Other organs besides the stomach, such as the colon or spleen, push up through the hiatus into the chest cavity.
Types II through IV are collectively called paraesophageal hernias. They are less common than sliding hernias but more likely to cause serious complications, including the stomach twisting on itself.
Epigastric Hernias
These occur along the midline of the abdomen, between the belly button and the breastbone. They push through the thin band of tissue that connects the left and right sides of your abdominal muscles. Epigastric hernias are usually small, sometimes only containing a bit of fat rather than intestine, and may cause a tender lump you can feel just above the navel. They don’t resolve on their own and typically require surgical repair if they cause pain.
Less Common Types
Spigelian Hernia
A Spigelian hernia pushes through the tissue separating the front abdominal muscles, typically appearing as a bulge 2 to 3 inches to the side of the belly button in the lower abdomen. These hernias are rare, usually appearing around age 50, with no strong preference for either sex. What makes them tricky is that the bulge often sits between muscle layers rather than poking outward under the skin, so it can be easy to miss on a standard physical exam. Chronic cough, constipation, obesity, pregnancy, and even direct trauma to the lower belly can trigger one.
Obturator Hernia
Obturator hernias push through a small opening in the pelvic bone. They occur most often in thin, elderly women and are more common on the right side. Because these hernias are deep within the pelvis, they rarely produce a visible bulge. Instead, they may cause inner thigh pain or unexplained bowel obstruction, making diagnosis a challenge without imaging.
When a Hernia Becomes Dangerous
Most hernias cause discomfort or a visible bulge but aren’t immediately dangerous. The concern is what happens if the protruding tissue gets stuck. An incarcerated hernia means the tissue is trapped and can no longer be pushed back into place, blocking the flow of intestinal contents. A strangulated hernia is more severe: blood supply to the trapped tissue is also cut off, which can lead to tissue death within hours. Strangulation causes sudden, intense pain, nausea, vomiting, and sometimes fever. It requires emergency surgery.
Risk Factors That Cut Across All Types
Certain factors make hernias of any type more likely. Obesity, aging, smoking, and diabetes are well-established contributors. Anything that repeatedly increases pressure inside the abdomen, such as chronic coughing, heavy lifting, straining during bowel movements, or pregnancy, can push tissue through a weak spot over time.
There is also a genetic component. People with connective tissue disorders like Ehlers-Danlos syndrome are at clearly elevated risk. Even in the general population, researchers have found that hernia tissue consistently shows a lower ratio of the two main types of structural collagen compared to healthy tissue, suggesting that some people are born with inherently weaker connective tissue. For inguinal hernias specifically, studies have identified 92 susceptible locations across 66 genes, many linked to immune function.
How Hernias Are Diagnosed
A doctor can often identify a groin or abdominal wall hernia during a physical exam, especially if you cough or bear down to make the bulge more visible. When the diagnosis is uncertain, or when the hernia is in a hard-to-examine location, imaging helps. Ultrasound is a common first step for both groin and abdominal wall hernias. CT scans provide more detail and are the go-to option for deep pelvic hernias like obturator hernias, which can’t be felt from the outside. MRI is sometimes used when other imaging is inconclusive.
Surgical Repair Options
Surgery is the only way to permanently fix a hernia. The two main approaches are open repair, where the surgeon makes an incision directly over the hernia, and laparoscopic repair, where several small incisions allow a camera and instruments to do the work. Both methods typically involve placing a mesh to reinforce the weakened area.
In a study comparing the two approaches in adults 65 and older, recurrence rates at one year were similar: about 1.5% for laparoscopic and 2.1% for open repair. Return to work took a median of 30 days with either technique. The meaningful difference was in short-term recovery. Patients who had laparoscopic repair left the hospital sooner and resumed normal daily activities faster. Not every hernia is suitable for the laparoscopic approach, particularly very large or complex hernias, but for straightforward repairs, the outcomes are comparable.