It is possible for a person to black out after standing suddenly due to low diastolic blood pressure, states MedlinePlus. Many other factors, including medications, can affect the blood pressure in day-to-day lives.
After changing position from lying down to standing up quickly, the body cannot react fast enough, and the drop in blood pressure triggers a sense of dizziness and may cause a blackout, states MedlinePlus. A healthy blood pressure reading ranges from 90/60 millimeters of mercury to 130/80 millimeters of mercury. Hypotension is the medical term for low blood pressure, which refers to any reading below this range.
Treatments for hypotension caused by position changes may include medication changes, increase of water intake and use of compression stockings, states MedlinePlus.