What is the critical risk factor for developing a hemorrhagic stroke?

High blood pressure, or hypertension, is identified as the critical risk factor for developing a hemorrhagic stroke due to its ability to weaken blood vessel walls over time. When blood pressure is elevated, it puts increased stress on the arterial walls, making them more susceptible to rupture. This rupture can lead to bleeding in the brain, which is the defining feature of a hemorrhagic stroke. Maintaining blood pressure within a healthy range is crucial for reducing the risk of such strokes.

Other factors listed, such as fatigue, age over 50, and high cholesterol levels, can contribute to overall cardiovascular health and the risk of strokes in different ways, but they are not as directly linked to the occurrence of hemorrhagic strokes as uncontrolled high blood pressure is. Fatigue may affect a person's overall health but does not directly cause vascular damage. Age is a general risk factor for many health issues, and while it relates to stroke risks, it does not specifically elevate the risk of a hemorrhagic stroke in the way high blood pressure does. High cholesterol is more associated with ischemic strokes, where a blood clot blocks a vessel, rather than causing the rupture of blood vessels characteristic of hemorrhagic strokes.