High and low blood pressure
Blood pressure that stays too high or too low harms the body.
High blood pressure (hypertension)
Pressure stays above normal.
Causes: narrowed arteries, too much salt, obesity, stress, smoking, alcohol.
It can lead to strokes, heart attacks and kidney failure.
Low blood pressure (hypotension)
Pressure stays below normal.
Causes: heavy blood loss, dehydration, poor nutrition.
Too little blood reaches the brain: dizziness and fainting.