1 If a lot of blood leaks out, it can cause a buildup of pressure in the brain because the brain is enclosed in the skull. There is no room for brain tissue to expand, and so the leaked blood can compress and kill important areas of the brain.  Hemorrhagic strokes tend to be more serious than ischemic strokes.
Horizontal definition, at right angles to the vertical; parallel to level ground. See more.
The usage of the inter-related terms horizontal and vertical as well as their symmetries and asymmetries vary with context. In astronomy, geography, and related sciences and contexts, a direction passing by a given point is said to be vertical if it is locally aligned with the local gravity vector at that point. In general, something that is vertical can be drawn from up to down, such as the y-axis in the Cartesian coordinate system.