**Core Concept**
Paraesophageal hernia is a type of hiatal hernia where the stomach protrudes through the esophageal hiatus in the diaphragm, alongside or behind the esophagus. This occurs when a portion of the stomach bulges through the diaphragm, potentially compromising blood flow to the stomach.

**Why the Correct Answer is Right**
Paraesophageal hernias often present with symptoms such as abdominal pain, nausea, and vomiting. The hernia occurs due to a weakness in the diaphragm, allowing the stomach to protrude. The risk of incarceration and strangulation increases with the size of the hernia. Early surgical repair is essential to prevent complications such as necrosis and perforation.

**Why Each Wrong Option is Incorrect**
**Option A:** Paraesophageal hernias are often asymptomatic and may not require immediate surgical repair, which is incorrect because early surgical repair is essential to prevent complications.

**Option B:** Paraesophageal hernias primarily occur in young individuals, which is incorrect because they are more common in older adults.

**Option C:** Paraesophageal hernias are a type of sliding hiatal hernia, which is incorrect because they are a type of hiatal hernia but sliding hernias occur when the gastroesophageal junction slides up into the chest.

**Clinical Pearl / High-Yield Fact**
Paraesophageal hernias can present with symptoms similar to gastroesophageal reflux disease (GERD), making it essential to consider this diagnosis in patients with atypical symptoms or a history of previous abdominal surgery.

**Correct Answer:** C.