Gaps - Breaks in the traffic stream long enough to permit vehicles or pedestrians access across or into the traffic stream. Gore - The V-shaped area that separates through-traffic from exiting or entering traffic on freeways and highways. Grade Separation - A crossing that uses an underpass or overpass to eliminate conflict points.
Although blood pressure varies from person to person, a blood pressure reading of 90 millimeters of mercury (mm Hg) or less systolic blood pressure (the top number in a blood pressure reading) or 60 mm Hg or less diastolic blood pressure (the bottom number) is generally considered low blood pressure.
Low blood pressure is blood pressure low enough to cause symptoms such as dizziness and fainting. Very low blood pressure can cause damage to organs, a process called shock. Various drugs and disorders can affect the body's system for maintaining blood pressure. When blood pressure is too low, the brain malfunctions, and fainting may occur.