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.
1. Of, relating to, or near the horizon. 2. a. Parallel to or in the plane of the horizon. b. At right angles to a vertical line. 3. Occupying or restricted to the same level in a hierarchy: a horizontal study of verbal ability; a horizontal transfer by an employee.orizontal. adj. 1. parallel to the plane of the horizon; level; flat. Compare vertical 1. 2. of or relating to the horizon.