Blood Pressure Checker — AHA Categories & Log
Last reviewed: April 2026
This blood pressure reference tool classifies your systolic and diastolic readings using the American Heart Association (AHA) 2017 guidelines — the most widely used standard for blood pressure categorization in the United States. Enter your systolic (top number) and diastolic (bottom number) readings to instantly see your category: Normal, Elevated, High Blood Pressure Stage 1, High Blood Pressure Stage 2, or Hypertensive Crisis. The tool also includes a full reference table of all categories with their numeric ranges, a color-coded gauge visualization, and a personal reading log that stores up to 10 entries locally on your device. Blood pressure readings can vary throughout the day based on activity, stress, caffeine, and other factors — a single reading is rarely enough for a clinical diagnosis. Always discuss your readings with your healthcare provider.
Enter Your Blood Pressure Reading
🔒 Your numbers stay in your browser — nothing is sent to any server.
A reading in this range requires immediate evaluation by a healthcare professional. If you are also experiencing chest pain, severe headache, shortness of breath, vision changes, or numbness, call emergency services (911) immediately. Do not wait.
AHA Blood Pressure Categories — Full Reference Table
| Category | Systolic | Diastolic | What it means | |
|---|---|---|---|---|
| Normal | Less than 120 | and | Less than 80 | Healthy range. Maintain with regular activity and balanced diet. |
| Elevated | 120 – 129 | and | Less than 80 | Likely to develop high BP without lifestyle changes. No medication typically needed yet. |
| High BP Stage 1 | 130 – 139 | or | 80 – 89 | Doctor may recommend lifestyle changes and possibly medication based on cardiovascular risk. |
| High BP Stage 2 | 140 or higher | or | 90 or higher | Doctor likely to prescribe medication and recommend lifestyle changes. Consult your doctor promptly. |
| Hypertensive Crisis | Higher than 180 | and/or | Higher than 120 | Seek immediate medical attention. If experiencing symptoms, call 911. |
Source: American Heart Association, 2017 Hypertension Guidelines. Note: Categories are for adults age 18+. Children and adolescents use different reference values.
Personal Reading Log
💾 Saved locally on your device only — never transmitted to any server (localStorage)
| Date | Reading | Category | Note | |
|---|---|---|---|---|
| No readings logged yet. Add your first reading above. | ||||
Tools that may help with blood pressure monitoring:
- OMRON Upper-Arm Blood Pressure Monitor — Clinically validated, the style recommended for home readings
- Blood Pressure Log Book — Track readings over time to share with your doctor
Affiliate disclosure: We may earn a commission if you sign up through these links, at no cost to you.
Understanding Your Blood Pressure Numbers
A blood pressure reading shows two numbers: systolic pressure (top) and diastolic pressure (bottom), measured in millimeters of mercury (mmHg). Systolic pressure is the force your heart exerts on artery walls when it contracts and pumps blood. Diastolic pressure is the pressure in your arteries between heartbeats, when the heart relaxes and refills.
The 2017 American Heart Association (AHA) and American College of Cardiology (ACC) guidelines define five categories. Normal is below 120/80. Elevated is 120–129 systolic with diastolic below 80. Hypertension Stage 1 begins at 130/80; Stage 2 at 140/90. Hypertensive crisis — above 180 systolic and/or above 120 diastolic — requires immediate medical attention. These thresholds reflect cardiovascular outcome data and represent a 2017 update from older cutoffs, which placed the Stage 1 threshold at 140/90.
A single home reading cannot diagnose hypertension. Clinical diagnosis requires multiple elevated readings taken under resting conditions on separate occasions with a validated device. If your reading falls in an elevated or hypertensive range, share results with your healthcare provider rather than drawing conclusions from one measurement.
What Can Affect a Single Reading
Blood pressure fluctuates naturally throughout the day based on activity, stress, posture, caffeine intake, temperature, and circadian rhythms. It is typically lowest during sleep, rises sharply upon waking, and peaks in the mid-afternoon. This variation is normal and expected in healthy people.
Several common factors can cause a temporary spike in an otherwise healthy person: recent physical exertion, caffeine or nicotine within 30 minutes, a full bladder, talking during the reading, sitting with an unsupported back or crossed legs, holding the arm above heart level, and using a cuff that is too small. "White-coat hypertension" — elevated readings only in clinical settings due to anxiety — affects a meaningful portion of people who appear hypertensive in office measurements but have normal home readings.
For a representative reading: rest quietly for 5 minutes before measuring; avoid caffeine and exercise for 30 minutes beforehand; sit with back supported and feet flat on the floor; position the cuff at heart level. Take two readings one minute apart and average them. Consistent readings over days and weeks are far more clinically meaningful than any single measurement.
Frequently Asked Questions
What is a normal blood pressure reading?
By the 2017 AHA/ACC guidelines, normal blood pressure is below 120/80 mmHg. Readings of 120–129 systolic with diastolic below 80 are classified as elevated — not yet hypertension, but associated with higher cardiovascular risk. Stage 1 hypertension starts at 130/80; Stage 2 at 140/90. A hypertensive crisis (above 180/120) requires immediate medical attention. These thresholds reflect population-level cardiovascular outcome data. A single reading outside the normal range does not constitute a diagnosis — consistent patterns over multiple readings matter more than any individual result.
Why does blood pressure vary throughout the day?
Blood pressure fluctuates naturally based on activity, stress, posture, caffeine intake, and circadian rhythms. It is typically lowest during sleep, rises sharply upon waking, and peaks in the afternoon. This variation is normal. A single elevated reading following a stressful morning does not mean you have hypertension. Clinical diagnosis requires multiple resting readings on separate occasions. Home monitoring over days and weeks gives a far more accurate picture of your typical blood pressure than any individual measurement.
What is the difference between systolic and diastolic pressure?
Systolic (top number) is the pressure in your arteries when the heart beats and pumps blood. Diastolic (bottom number) is the pressure between beats when the heart rests and refills. Both numbers matter: elevated systolic pressure is a primary cardiovascular risk factor, especially in adults over 50; elevated diastolic is more predictive of risk in younger adults. Hypertension is diagnosed if either number is consistently above the threshold — 130 systolic or 80 diastolic by 2017 AHA guidelines — not necessarily both at the same time.
How do I take an accurate blood pressure reading at home?
For an accurate home reading: rest quietly for 5 minutes beforehand; avoid caffeine, exercise, and smoking for 30 minutes; sit with your back supported and feet flat on the floor; position the cuff on your upper arm at heart level; use a validated upper-arm cuff (wrist monitors are less accurate). Take two readings one minute apart and average them. Measure at the same time each day — ideally morning before medication and evening before dinner. Bring your monitor to your provider to verify its accuracy against a clinical device. Consistently elevated home readings above 130/80 warrant a conversation with your healthcare provider.
Related Calculators
Sources & Methodology
Classification used: 2017 American Heart Association (AHA) / American College of Cardiology (ACC) High Blood Pressure Clinical Practice Guidelines. Categories: Normal (<120/<80) · Elevated (120–129/<80) · Hypertension Stage 1 (130–139 or 80–89) · Hypertension Stage 2 (≥140 or ≥90) · Hypertensive Crisis (>180 and/or >120).
Sources: Whelton PK, et al. (2018). 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults. Hypertension. 71(6):1269–1324. A single home reading cannot diagnose hypertension — clinical diagnosis requires multiple readings over time with a validated device.
Last reviewed: April 2026