| | |  | | © Reed Group | | | A hiatal hernia is the protrusion (prolapse) of a portion of the stomach through the junction between the diaphragm and the esophagus (diaphragmatic esophageal hiatus). The diaphragm is a sheet of muscle and tendons that separates the chest and abdominal cavities and keeps the contents of those cavities separated. The hiatus, where the esophagus passes through the diaphragm, is a potential weak spot in the diaphragm. A hiatal hernia occurs when the stomach protrudes (herniates) into the chest cavity through the hiatus as a result of increased intra-abdominal pressure. Any repetitive action that increases pressure in the abdominal cavity, including chronic coughing, prolonged vomiting, straining during bowel movements, and sudden exertion, may result in hiatal hernia.
Hiatal hernias are common and in most cases go unnoticed. Over half of individuals who develop hiatal hernia will remain symptom-free. However, when the condition coexists with gastroesophageal reflux disease (GERD), in which stomach acid backflows into the esophagus, the condition may become exaggerated and can progress to acute and sometimes life-threatening conditions such as gastric volvulus or strangulation. Individuals with GERD may have more pronounced symptoms from hiatal hernia than those without GERD because the hiatal hernia traps the fluids of gastric reflux and increases the period of contact between the stomach acid and the esophagus.
Generally, there are two types of hiatal hernia: sliding (type I) and paraesophageal or rolling (type II). A mixed hiatal hernia (type III) combines the two types. Sliding hiatal hernias occur when the place where the esophagus joins the stomach (gastroesophageal junction), which normally is situated below the diaphragm, slides into the chest cavity. A sliding hiatal hernia is more likely to be associated with GERD. Paraesophageal hiatal hernia occurs when the gastroesophageal junction remains in place, but a portion of the stomach herniates into the chest cavity. Occasionally, an individual may present with a mixed hiatal hernia, which occurs when almost all of the stomach herniates into the chest cavity. In this case, the gastroesophageal junction may lie either above or below the diaphragm. If a small portion of the small intestine also protrudes through the diaphragm along with the stomach, the hernia is referred to as a type IV hernia.
Approximately 99% percent of hiatal hernias are sliding, and 1% is paraesophageal; the other types are very rare (Quereshi).
Incidence and Prevalence: Hiatal hernia occurs primarily in developed countries that consume a Western diet low in fiber (Quereshi). |
Source: Medical Disability Advisor