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.
Definition: A straight line on the coordinate plane where all points on the line have the same y-coordinate. Try this Drag the points A or B and note the line is horizontal when they both have the same y-coordinate. A horizontal line is one the goes left-to-right, parallel to the x-axis of the coordinate plane. All points on the line will have the same y-coordinate. In the figure above, drag either point and note that the line is horizontal when they both have the same y-coordinate. A horizontal line has a slope of zero.