Blood pressure is a vital sign that measures the force of blood pushing against the walls of your arteries. It's recorded as two numbers: the systolic pressure (the higher number) and the diastolic pressure (the lower number). The units are millimeters of mercury (mmHg).
Maintaining healthy blood pressure is crucial for preventing serious health issues like heart disease, stroke, kidney failure, and vision loss. The American Heart Association (AHA) and other health organizations provide guidelines for classifying blood pressure readings into different categories.
How the Calculator Works:
This calculator uses the standard guidelines to categorize your blood pressure based on the systolic and diastolic readings you provide. It checks your values against established thresholds to determine the most appropriate category.
Blood Pressure Categories and Thresholds:
Normal: Less than 120 systolic AND less than 80 diastolic.
Elevated: 120-129 systolic AND less than 80 diastolic.
Hypertension Stage 1: 130-139 systolic OR 80-89 diastolic.
Hypertension Stage 2: 140 or higher systolic OR 90 or higher diastolic.
Hypertensive Crisis: Higher than 180 systolic AND/OR higher than 120 diastolic. (Requires immediate medical attention)
Interpreting Your Results:
The category displayed by the calculator is a general guideline. Your doctor will consider your overall health, medical history, and other factors when diagnosing and managing blood pressure.
Important Note: This calculator is for informational purposes only and should not be used as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.
function calculateBloodPressureCategory() {
var systolicInput = document.getElementById("systolic");
var diastolicInput = document.getElementById("diastolic");
var systolic = parseFloat(systolicInput.value);
var diastolic = parseFloat(diastolicInput.value);
var resultValueElement = document.getElementById("result-value");
var resultCategoryElement = document.getElementById("result-category");
// Clear previous results
resultValueElement.innerHTML = "–";
resultCategoryElement.innerHTML = "–";
// Validate inputs
if (isNaN(systolic) || isNaN(diastolic) || systolic <= 0 || diastolic = 180 || diastolic >= 120) {
category = "Hypertensive Crisis";
resultCategoryElement.style.color = "#dc3545"; // Red for crisis
} else if (systolic >= 140 || diastolic >= 90) {
category = "Hypertension Stage 2";
resultCategoryElement.style.color = "#ffc107"; // Amber for high stage
} else if (systolic >= 130 || diastolic >= 80) {
category = "Hypertension Stage 1";
resultCategoryElement.style.color = "#fd7e14"; // Orange for stage 1
} else if (systolic >= 120 && diastolic < 80) {
category = "Elevated";
resultCategoryElement.style.color = "#17a2b8"; // Info color
} else if (systolic < 120 && diastolic < 80) {
category = "Normal";
resultCategoryElement.style.color = "#28a745"; // Green for normal
} else {
// Fallback for any unhandled edge cases, though the logic should cover standard ranges
category = "Category Unclear";
resultCategoryElement.style.color = "#6c757d"; // Grey for unclear
}
resultValueElement.innerHTML = displayValue;
resultCategoryElement.innerHTML = category;
}