Diaphragmatic injuries are present in 1–7% of people with significant blunt trauma and an average of 3% of abdominal injuries.

A high body mass index may be associated with a higher risk of diaphragmatic rupture in people involved in vehicle accidents. It is rare for the diaphragm alone to be injured, especially in blunt trauma; other injuries are associated in as many as 80–100% of cases. In fact, if the diaphragm is injured, it is an indication that more severe injuries to organs may have occurred. Thus, the mortality after a diagnosis of diaphragmatic rupture is 17%, with most deaths due to lung complications. Common associated injuries include head injury, injuries to the aorta, fractures of the pelvis and long bones, and lacerations of the liver and spleen. Associated injuries occur in over three quarters of cases.

A significant complication of diaphragmatic rupture is traumatic diaphragmatic herniation: organs such as the stomach that herniate into the chest cavity and may be strangulated, losing their blood supply. Herniation of abdominal organs is present in 3–4% of people with abdominal trauma who present to a trauma center.

Treatment for a diaphragmatic hernia usually involves surgery, with acute injuries often repaired with monofilament permanent sutures.

No treatment is needed for correcting lung hernias. Some surgeons offer cosmetic surgery to remove the protruding mass.

Diaphragmatic hernia is a defect or hole in the diaphragm that allows the abdominal contents to move into the chest cavity. Treatment is usually surgical.

Lung hernia (Sibson hernia) is a protrusion of lung outside of thoracic wall. In 20% patients with lung hernia, the incidence is congenital. In 80% of the cases, the hernia is noted after chest trauma, thoracic surgery or certain pulmonary diseases. Congenital hernia occurs because of the weakness of the suprapleural membrane or neck muscles. In pulmonary diseases such as asthma, frequent coughing can lead to high intra thoracic pressure, causing the lung to herniate out. Lung hernia may occur near the neck (cervical), between the ribs (intercostal), near the vertebrae (paravertebral) or near the sternum (parasternal).

Congenital diaphragmatic hernia has a mortality rate of 40–62%, with outcomes being more favorable in the absence of other congenital abnormalities. Individual rates vary greatly dependent upon multiple factors: size of hernia, organs involved, additional birth defects, and/or genetic problems, amount of lung growth, age and size at birth, type of treatments, timing of treatments, complications (such as infections) and lack of lung function.

Petit's hernia is a hernia that protrudes through the lumbar triangle. This triangle lies in the posterolateral abdominal wall and is bounded anteriorly by the free margin of external oblique muscle, posteriorly by the latissimus dorsi and inferiorly by the iliac crest. The neck (the spot where the hernia protrudes into the opening) is large, and therefore this hernia has a lower risk of strangulating than some other hernias.

Petit's hernia occurs more often in males than in females and more often on the left side than on the right.

Diastasis recti (also known as abdominal separation) is commonly defined as a gap of roughly 2.7 cm or greater between the two sides of the rectus abdominis muscle. This condition has no associated morbidity or mortality.

The distance between the right and left rectus abdominis muscles is created by the stretching of the linea alba, a connective collagen sheath created by the aponeurosis insertions of the transverse abdominis, internal oblique, and external oblique.

Diastasis of this muscle occurs principally in two populations: newborns and pregnant women. It is also known to occur in men.

- In the newborn, the rectus abdominis is not fully developed and may not be sealed together at midline. Diastasis recti is more common in premature and black newborns.

- In pregnant or postpartum women, the condition is caused by the stretching of the rectus abdominis by the growing uterus. It is more common in multiparous women due to repeated episodes of stretching. When the defect occurs during pregnancy, the uterus can sometimes be seen bulging through the abdominal wall beneath the skin.

- Women are more susceptible to develop diastasis recti when over the age of 35, high birth weight of child, multiple birth pregnancy, and multiple pregnancies. Additional causes can be attributed to excessive abdominal exercises after the first trimester of pregnancy.

Bochdalek hernias make up about 0.17% to 6% of all diaphragmatic hernia cases and about one in every 2200 to 12,500 births every year. Babies who are born with a Bochdalek hernia are more than likely to have another birth defect caused by the hernia. About twenty percent of those children born with a Bochdalek hernia, also have a congenital heart defect. In addition, infants born with this condition may also have other abnormalities. "Between five and sixteen [percent of infants] have a chromosomal abnormality." In most cases, left-sided hernias or Bochdalek hernias have a ratio of 3:2 of males to females. In other words, Bochdalek hernias are more common in men.

Bochdalek hernia can be a life-threatening condition. Approximately 85.3% of newborns born with a Bochdalek hernia are immediately high risk. Infants born with a Bochdalek hernia have a "high mortality rate due to respiratory insufficiency". Between 25–60% of infants with a Bochdalek hernia die. The lungs, diaphragm, and digestive system are all forming at the same time, so when a Bochdalek hernia permits the abdominal organs to invade the chest cavity rather than remain under the diaphragm in the correct position, it puts the infant in critical condition. These "foreign bodies" in the chest cavity compress the lungs, impairing their proper development and causing pulmonary hypoplasia. Since the lungs of infants suffering from a Bochdalek hernia have fewer alveoli than normal lungs, Bochdalek hernias are life-threatening conditions due to respiratory distress. Also, if the invasion of the intestine or stomach punctures the lung, then the lungs cannot fill completely with air. The baby will not be healthy or stable with this condition because he or she cannot take in enough air and oxygen to keep the body operating properly. Like the lungs, the intestines may also have trouble developing correctly. If the intestines are trapped within the lungs, then the lungs and intestines may not be receiving the amount of blood they need to stay healthy and function properly.

The protrusion is put back within the abdomen in the correct position. Stitches are used to strengthen the weakness where the hernia has broken through.

The operation is usually performed under a general anaesthetic.

In most cases this is done as a day case without the need for an overnight stay.

Internal hernias occur when there is protrusion of an internal organ into a retroperitoneal fossa or a foramen (congenital or acquired) in the abdominal cavity. If a loop of bowel passes through the mesenteric defect, that loop is at risk for incarceration, strangulation, or for becoming the lead point of a small bowel obstruction. Internal hernias can also trap adipose tissue (fat) and nerves. Unlike more common forms of hernias, the trapped tissue protrudes inward, rather than outward.

Mesenteric defects commonly occur in trauma, such as gunshot wounds to the abdomen. In trauma victims, the defect is usually closed, sometimes with resection of the associated bowel, which may have lost its blood supply. Also mesenteric defects are intentionally created in the Roux-en-Y gastric bypass procedure, being classically known as a Petersen's hernia. The mesenteric defect in such cases, called "Petersen's defect", is located between the transverse colon and the mesentery of the alimentary limb (the segment of the jejunum from the jejunojejunostomy until the connection with the proximal segment of the stomach) at the level of the jejunojejunostomy.

Internal hernias are difficult to identify in women, and misdiagnosis with endometriosis or idiopathic chronic pelvic pain is very common. One cause of misdiagnosis that when the woman lies down flat on an examination table, all of the medical signs of the hernia disappear. The hernia can typically only be detected when symptoms are present, so diagnosis requires positioning the woman's body in a way that provokes symptoms.

Both internal hernias and umbilical hernias are more common in women than men.

Incisional hernias are usually caused by a weakness of the surgical wounds, which may be caused by hematoma, seroma, or infection, all of which result in decreased wound healing. They may also be caused by increased intra-abdominal pressure due to a chronic cough (as in COPD), constipation, urinary obstruction (as in BPH), pregnancy, or ascites. They can also result from poor surgical technique.

Many people are managed through day surgery centers, and are able to return to work within a week or two, while intense activities are prohibited for a longer period. People who have their hernias repaired with mesh often recover within a month, though pain can last longer. Surgical complications include pain that lasts more than three months, surgical site infections, nerve and blood vessel injuries, injury to nearby organs, and hernia recurrence. Pain that lasts more than three months occurs in about 10% of people following hernia repair.

A paraumbilical (or umbilical) hernia is a protrusion of the abdominal contents, including mesenteric fat or bowel, through a weak point of the muscles or ligaments near the navel. It can lead to discomfort when fatty tissue gets trapped and a lump can be felt or seen. Whilst they are not usually life-threatening, routine surgical treatment is usually advised to prevent enlargement or strangulation or obstruction of the gut. Women are more frequently affected than men.

An epigastric hernia is a type of hernia which may develop in the epigastrium (upper, central part of the abdomen). Epigastric hernias usually appear in adults.

Unlike the benign diastasis recti, epigastric hernia may trap fat and other tissues inside the opening of the hernia, causing pain and tissue damage.

Congenital diaphragmatic hernia (CDH) is a birth defect of the diaphragm. The most common type of CDH is a Bochdalek hernia; other types include Morgagni hernia, diaphragm eventration and central tendon defects of the diaphragm. Malformation of the diaphragm allows the abdominal organs to push into the chest cavity, hindering proper lung formation.

CDH is a life-threatening pathology in infants and a major cause of death due to two complications: pulmonary hypoplasia and pulmonary hypertension. Experts disagree on the relative importance of these two conditions, with some focusing on hypoplasia, others on hypertension. Newborns with CDH often have severe respiratory distress which can be life-threatening unless treated appropriately.

In some cases (particularly where whole litters are affected) FCKS can be due to genetic factors: certain bloodlines are known to produce a preponderance of kittens with the condition, and close matings very commonly produce it in the offspring. Isolated cases are more likely due to environmental factors or slight prematurity of the kittens concerned, and even complete litters suffering from FCKS may have no genetic component—repeat matings that have produced flat kittens in one instance have often not produced it again, and recovered FCKS that have been bred from have likewise not necessarily produced offspring that suffered from the condition.

These hernias should be repaired because of the high risk of strangulation; fortunately, surgery is straightforward, with only larger defects requiring a mesh prosthesis. Varied Spigelian hernia mesh repair techniques have been described, although evidence suggests laparoscopy results in less morbidity and shorter hospitalization compared with open procedures. Mesh-free laparoscopic suture repair is feasible and safe. This novel uncomplicated approach to small Spigelian hernias combines the benefits of laparoscopic localization, reduction, and closure without the morbidity and cost associated with foreign material.

A hernia is the abnormal exit of tissue or an organ, such as the bowel, through the wall of the cavity in which it normally resides. Hernias come in a number of different types. Most commonly they involve the abdomen, specifically the groin. Groin hernias are most common of the inguinal type but may also be femoral. Other hernias include hiatus, incisional, and umbilical hernias. Symptoms are present in about 66% of people with groin hernias. This may include pain or discomfort especially with coughing, exercise, or going to the bathroom. Often it gets worse throughout the day and improves when lying down. A bulging area may occur that becomes larger when bearing down. Groin hernias occur more often on the right than left side. The main concern is strangulation, where the blood supply to part of the bowel is blocked. This usually produces severe pain and tenderness of the area. Hiatus or hiatal hernias often result in heartburn but may also cause chest pain or pain with eating.

Risk factors for the development of a hernia include: smoking, chronic obstructive pulmonary disease, obesity, pregnancy, peritoneal dialysis, collagen vascular disease, and previous open appendectomy, among others. Hernias are partly genetic and occur more often in certain families. It is unclear if groin hernias are associated with heavy lifting. Hernias can often be diagnosed based on signs and symptoms. Occasionally medical imaging is used to confirm the diagnosis or rule out other possible causes. The diagnosis of hiatus hernias is often by endoscopy.

Groin hernias that do not cause symptoms in males do not need to be repaired. Repair, however, is generally recommended in women due to the higher rate of femoral hernias which have more complications. If strangulation occurs immediate surgery is required. Repair may be done by open surgery or by laparoscopic surgery. Open surgery has the benefit of possibly being done under local anesthesia rather than general anesthesia. Laparoscopic surgery generally has less pain following the procedure. A hiatus hernia may be treated with lifestyle changes such as raising the head of the bed, weight loss, and adjusting eating habits. The medications, H2 blockers or proton pump inhibitors may help. If the symptoms do not improve with medications the surgery known as laparoscopic fundoplication may be an option.

About 27% of males and 3% of females develop a groin hernia at some time in their life. Inguinal, femoral and abdominal hernias were present in 18.5 million people and resulted in 59,800 deaths in 2015. Groin hernias occur most often before the age of one and after the age of fifty. It is not known how commonly hiatus hernias occur with estimates in North America varying from 10 to 80%. The first known description of a hernia dates back to at least 1550 BC in the Ebers Papyrus from Egypt.

An acquired umbilical hernia directly results from increased intra-abdominal pressure caused by obesity, heavy lifting, a long history of coughing, or multiple pregnancies.

Grynfeltt-Lesshaft hernia is a herniation of abdominal contents through the back, specifically through the superior lumbar triangle, which is defined by the quadratus lumborum muscle, twelfth rib, and internal oblique muscle.

Traditional "open" repair of incisional hernias can be quite difficult and complicated. The weakened tissue of the abdominal wall is re-incised and a repair is reinforced using a prosthetic mesh. Complications, particularly infection of the incision, frequently occur because of the large size of the incision required to perform this surgery. A mesh infection after this type of hernia repair most frequently requires a complete removal of the mesh and ultimately results in surgical failure. In addition, large incisions required for open repair are commonly associated with significant postoperative pain. Reported recurrence rates after open repair are up to 20% and influenced by mesh size and fixation type.

Laparoscopic incisional hernia repair is a new method of surgery for this condition. The operation is performed using surgical microscopes and specialized instruments. The surgical mesh is placed into the abdomen underneath the abdominal muscles through small incisions to the side of the hernia. In this manner, the weakened tissue of the original hernia is never re-incised to perform the repair, and one can minimize the potential for wound complications such as infections. In addition, performance of the operation through smaller incisions can make the operation less painful and speed recovery. Laparoscopic repair has been demonstrated to be safe and a more resilient repair than open incisional hernia repair.

Symptomatic epigastric hernias are repaired with surgery. Even if they are asymptomatic, they can be surgically corrected for cosmetic reasons. In general, cosmetic surgery on infants is delayed until the infant is older and better able to tolerate anaesthesia.