What is the primary cause of infarction?

The primary cause of infarction is the reduction of blood supply to a specific area of tissue or an organ. Infarction occurs when the blood flow is insufficient to meet the metabolic needs of the cells, leading to cell death. This condition can be the result of various factors, such as a blockage in the blood vessels (due to a blood clot or plaque buildup) or severe narrowing of the arteries.

When blood supply is compromised, the delivery of oxygen and essential nutrients to tissues is diminished, which is critical for maintaining cellular function and viability. If tissues become ischemic (lacking adequate blood flow) for a prolonged period, they will eventually undergo necrosis, or tissue death, leading to an infarct.

Other options mentioned do not primarily cause infarction. For instance, bacterial infections can lead to inflammation and damage to tissues but do not directly affect blood supply in the same manner. Increased fluid retention might alter circulation dynamics but is not a direct cause of infarction. Nutritional deficiencies can impair overall health and healing but do not directly lead to infarction themselves. Thus, the reduction of blood supply is a defining characteristic of infarction and its underlying pathology.