Diastolic Blood Pressure

Diastolic blood pressure is the 'lower number', the pressure in your arteries between heartbeats when the heart is relaxed. Unlike systolic BP, diastolic BP peaks around age 50 and declines thereafter. Data are from NHANES 2001-2008 (n=19,921), a nationally representative survey of US adults. Because hypertension prevalence varies widely by country (NCD-RisC, Lancet 2021), the upper percentiles may not generalize to all populations.

These percentiles show where a reading sits in the population; they are not a clinical classification. Blood pressure is clinically interpreted using published guideline categories, which differ between the ACC/AHA 2017 and 2018 ESC/ESH guidelines, and is based on repeated measurements and individual context. Interpret an individual reading with a qualified clinician. Read more on Wikipedia

How to Perform This Test (Protocol)

Equipment
  • Calibrated sphygmomanometer or validated automated BP monitor
  • Appropriately sized cuff
Protocol Steps
  1. Sit quietly for 5 minutes before measuring, back supported, feet flat on the floor.
  2. Place the cuff on the upper arm, at heart level.
  3. Do not talk during the measurement.
  4. Take 2-3 readings spaced at least 1 minute apart.
Scoring

Record diastolic pressure (the lower number) in mmHg. Average the readings taken (NHANES averaged up to 3 consecutive readings, follow the protocol of your measurement setting).

Notes

Avoid caffeine, exercise, and smoking for 30 minutes before measuring. Both systolic and diastolic are typically recorded together from the same measurement session.

Data source: Wright et al. - NHANES Blood Pressure (NCHS Report #035) (2011) · n=19.9K About this study

Reference population: US adults aged 18 and over, nationally representative (NHANES 2001-2008)

Diastolic Blood Pressure Cardiovascular

Diastolic Blood Pressure Norms Chart by Age and Sex (mmHg)

Age Sex Percentile
5th 25th 50th 75th 95th
20-29 Male 56 66 72 80 90
Female 52 62 68 76 86
30-39 Male 60 70 76 84 94
Female 56 66 72 78 88
40-49 Male 62 72 78 86 96
Female 58 68 74 80 92
50-59 Male 60 70 76 84 94
Female 58 68 74 80 92
60-69 Male 56 66 72 80 92
Female 54 64 70 78 90
70-79 Male 50 60 68 76 88
Female 48 58 66 74 86
80+ Male 46 56 64 72 84
Female 44 54 62 70 82

What to expect by age group

Among adults in their 30s, the middle 50% measure 70 to 84 mmHg for men and 66 to 78 mmHg for women. Unlike systolic BP, diastolic BP peaks around age 40 to 50 and falls in older adults as arterial stiffness reduces the elastic recoil between heartbeats; men tend to run a few mmHg higher than women. These are population percentiles, not clinical categories; blood pressure is interpreted using published guideline thresholds and a clinician's assessment.

Typical range (25th to 75th percentile) by age group (mmHg)
Age MalesFemales
20-29 66 to 8062 to 76
30-39 70 to 8466 to 78
40-49 72 to 8668 to 80
50-59 70 to 8468 to 80
60-69 66 to 8064 to 78
70-79 60 to 7658 to 74
80+ 56 to 7254 to 70

Detailed Breakdowns

Select an age group and sex below for detailed percentile charts and distribution labels.

Males
20-2930-3940-4950-5960-6970-7980+
Females
20-2930-3940-4950-5960-6970-7980+
Age trend (percentiles)

Frequently Asked Questions

What is diastolic blood pressure?

Diastolic blood pressure is the 'lower number' in a blood pressure reading. It measures the pressure in your arteries between heartbeats, when the heart muscle is relaxed (diastole) and refilling with blood.

What are the AHA blood pressure categories for diastolic?

Blood pressure categories are defined by clinical guidelines, not by population percentiles, and the major guidelines differ: see the ACC/AHA 2017 and 2018 ESC/ESH guidelines for the official thresholds. A person's category follows whichever component, systolic or diastolic, falls in the higher guideline category (so isolated systolic or isolated diastolic elevation still counts), normally confirmed across repeated measurements. Separately, a systolic reading above 180 mmHg or a diastolic reading above 120 mmHg can signal a hypertensive crisis that may need immediate medical attention, not a repeat visit. We report where a value sits in the population, not a clinical category; interpret an individual reading with a qualified clinician.

Why does diastolic blood pressure decrease after age 50?

Diastolic pressure depends on arterial recoil, the elastic 'snap back' of artery walls between heartbeats that maintains pressure. As arteries stiffen with age, they lose this elastic recoil, so pressure between beats drops. This is why older adults often have a wide 'pulse pressure' (high systolic, lower diastolic).

How was blood pressure measured in this study?

NHANES examiners followed a standardized protocol: participants sat quietly for 5 minutes, then up to 3 consecutive readings were taken with a mercury sphygmomanometer. The readings were averaged. This protocol tends to produce slightly lower values than a single office reading, since the resting period and averaging reduce the effect of white-coat anxiety.

Why might these percentiles not apply outside the US?

This data comes from NHANES, a US-only survey. Blood pressure distributions vary substantially across countries, age-standardized mean diastolic BP differs by region, and hypertension prevalence ranges widely globally (NCD-RisC, Lancet 2021). The upper percentiles in particular may not generalize to populations with different dietary and lifestyle patterns.

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