What is the minimum diastolic blood pressure?
For instance, when the heart is pushing the blood round the body, your blood pressure can reach a top or maximum (systolic) level of anywhere between 90 to 240 mmHg and, when your heart is relaxing, your blood pressure can fall to a bottom or minimum (diastolic) level of between 40 to 160 mmHg.
Most doctors will only consider chronically low blood pressure as dangerous if it causes noticeable signs and symptoms, such as:
- Dizziness or lightheadedness.
- Fainting (syncope)
- Dehydration and unusual thirst.
- Dehydration can sometimes cause blood pressure to drop.
- Lack of concentration.
- Blurred vision.
- Most doctors consider blood pressure too low only if it causes symptoms. Some experts define low blood pressure as readings lower than 90 mm Hg systolic or 60 mm Hg diastolic. If either number is below that, your pressure is lower than normal. A sudden fall in blood pressure can be dangerous.
- The top number refers to the amount of pressure in your arteries during the contraction of your heart muscle. This is called systolic pressure. The bottom number refers to your blood pressure when your heart muscle is between beats. This is called diastolic pressure.
- Generally, if the blood pressure reading is under 90/60 mm Hg, it is abnormally low and is referred to as hypotension. Some adults regularly have a blood pressure in the hypotensive range, but have no symptoms at all and do not require treatment.
Updated: 6th December 2019