Convert blood pressure units, understand hypertension, and monitor cardiovascular health
This tool is for educational purposes only and should not replace professional medical advice. Blood pressure can vary throughout the day. Always consult your healthcare provider for diagnosis, treatment, or concerns about blood pressure. Seek immediate medical attention for hypertensive crisis (>180/120).
The American Heart Association updated guidelines in 2017, lowering the threshold for hypertension diagnosis to help prevent cardiovascular disease earlier.
Less than 120/80
Systolic: <120 AND
Diastolic: <80
120-129/<80
Systolic: 120-129 AND
Diastolic: <80
130-139/80-89
Systolic: 130-139 OR
Diastolic: 80-89
140/90 or higher
Systolic: ≥140 OR
Diastolic: ≥90
Higher than 180/120
Requires immediate
medical attention
Blood pressure is the force exerted by circulating blood against the walls of blood vessels. It's measured in millimeters of mercury (mmHg) and expressed as two numbers: systolic over diastolic pressure.
Systolic Pressure (top number) measures the pressure when your heart contracts and pumps blood into the arteries. This is the maximum pressure in your circulatory system.
Diastolic Pressure (bottom number) measures the pressure when your heart relaxes between beats. This represents the minimum pressure in your arteries.
While mmHg is the medical standard worldwide, other pressure units are sometimes used in scientific or engineering contexts:
| Category | Systolic (mmHg) | Diastolic (mmHg) | Action Needed |
|---|---|---|---|
| Normal | Less than 120 | Less than 80 | Maintain healthy lifestyle |
| Elevated | 120-129 | Less than 80 | Lifestyle changes recommended |
| Stage 1 Hypertension | 130-139 | 80-89 | Lifestyle + possible medication |
| Stage 2 Hypertension | 140 or higher | 90 or higher | Lifestyle + medication likely |
| Hypertensive Crisis | Higher than 180 | Higher than 120 | Immediate medical attention |
Pulse Pressure is the difference between systolic and diastolic pressure. Normal pulse pressure is 30-50 mmHg. Very high or low pulse pressure can indicate cardiovascular problems.
Mean Arterial Pressure (MAP) estimates the average pressure in arteries during one cardiac cycle. It's calculated as: MAP = Diastolic + (Pulse Pressure ÷ 3). Normal MAP is 70-100 mmHg.
Age and Gender: Blood pressure typically increases with age as arteries become less flexible. Men tend to have higher blood pressure earlier in life, while women's risk increases after menopause.
Physical Activity: Regular exercise strengthens the heart and can lower blood pressure. However, blood pressure temporarily rises during exercise and may remain elevated for several hours afterward.
Diet and Sodium: High sodium intake increases blood pressure in salt-sensitive individuals. The DASH diet (rich in fruits, vegetables, and low-fat dairy) has been proven to lower blood pressure.
Stress and Sleep: Chronic stress and poor sleep quality both contribute to elevated blood pressure. Stress hormones cause blood vessels to constrict and heart rate to increase.
Medications and Substances: Many medications affect blood pressure, including NSAIDs, birth control pills, decongestants, and some antidepressants. Caffeine, alcohol, and tobacco also influence readings.
Accurate measurement is crucial for proper diagnosis and management:
Blood pressure below 90/60 mmHg may cause symptoms, though some people naturally have low blood pressure without issues. Symptoms include:
High blood pressure often has no symptoms, earning its nickname as the "silent killer." Over time, untreated hypertension damages blood vessels and organs, leading to:
DASH Diet: Emphasizes fruits, vegetables, whole grains, lean proteins, and low-fat dairy while limiting sodium, saturated fat, and added sugars.
Regular Exercise: At least 150 minutes of moderate-intensity aerobic activity weekly, plus muscle-strengthening activities twice weekly.
Weight Management: Even modest weight loss (5-10 pounds) can significantly lower blood pressure in overweight individuals.
Stress Management: Techniques like meditation, deep breathing, yoga, or regular relaxation can help reduce stress-related blood pressure spikes.
Limit Alcohol and Quit Smoking: Moderate alcohol consumption (if any) and complete smoking cessation are essential for cardiovascular health.
When lifestyle changes aren't sufficient, several medication classes are available:
Crisis: >180/120 mmHg
Severe Low: <60/40 mmHg
Seek immediate medical help
General: <120/80 mmHg
Diabetes: <130/80 mmHg
Elderly: <150/90 mmHg (often)
Same time daily
Before medications
Record multiple readings
120 mmHg ≈ 16.0 kPa
80 mmHg ≈ 10.7 kPa
Divide mmHg by 7.5 for kPa
Immediate Emergency (Call 911): Blood pressure above 180/120 with symptoms like chest pain, shortness of breath, severe headache, or vision changes.
Urgent Care: Blood pressure above 180/120 without symptoms - contact your healthcare provider immediately.
Schedule Appointment: Consistently elevated readings above 130/80, new symptoms, or medication side effects.
Regular Monitoring: Adults should have blood pressure checked at least every 2 years if normal, more frequently if elevated or on medication.