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.
Question: Which way is horizontal? Which way is horizontal is a common question. Horizontal is left to right or east to west, or flat on the surface. Many people remember it by thinking about looking out over the horizon, which is flat, or goes from side to side, and horizon sounds like horizontal. Others look at the first letter H, and see how it has a line on either side indicating start and stop point, and then a flat line in between.