**Core Concept**
Absolute indications for hemodialysis in chronic kidney disease (CKD) are life-threatening conditions that cannot be managed with medical therapy alone, requiring immediate intervention to prevent mortality. These indications involve severe electrolyte imbalances, fluid overload, or uremia.

**Why the Correct Answer is Right**
Uremic pericarditis is a serious complication of CKD characterized by inflammation of the pericardium, often resulting from the accumulation of uremic toxins in the blood. This condition can lead to cardiac tamponade, a life-threatening condition requiring immediate intervention. Hemodialysis is the most effective treatment for uremic pericarditis, allowing for rapid removal of uremic toxins and prevention of cardiac complications.

**Why Each Wrong Option is Incorrect**
**Option A:** Hyperkalemia is a common electrolyte imbalance in CKD, but it is not an absolute indication for hemodialysis unless severe (typically > 6.5 mmol/L) and refractory to medical management.
**Option B:** Fluid overload is a common complication of CKD, but it is typically managed with diuretics and other medical therapies before considering hemodialysis.
**Option C:** Anemia is a common complication of CKD, but it is not an absolute indication for hemodialysis. Other treatments, such as erythropoiesis-stimulating agents and iron supplementation, are usually effective.

**Clinical Pearl / High-Yield Fact**
Uremic pericarditis is a classic absolute indication for hemodialysis in CKD, and prompt recognition and treatment are critical to prevent cardiac complications.

**Correct Answer: C. Uremic pericarditis.**