Blood pressure (diastolic)

Below 90 mmHg in clinic, below 85 at home, on UK thresholds.

Diastolic blood pressure is the lower number, the pressure in the arteries between heartbeats.

Measured with systolic at every blood pressure check, in clinic and at home.

• The same everyday factors as systolic
• Being overweight, alcohol, high salt intake

• Blood pressure medicines as a class
• Increasing age, as arteries stiffen, which widens the gap between the two numbers
• Dehydration

• It tends to fall after middle age even as systolic rises
• A cuff that is too small reads high

Same conditions as systolic.

Written by a UK consultant physician. Typical UK adult reference ranges; your laboratory's own printed range takes precedence.