Estimate your 10-year risk of developing Coronary Heart Disease based on key health factors.
Male
Female
Non-smoker
Ex-smoker
Current Smoker
No
Yes
Your Estimated 10-Year CHD Risk:
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This is an estimate and not a substitute for professional medical advice.
Understanding Coronary Heart Disease (CHD) Risk
Coronary Heart Disease (CHD), also known as ischemic heart disease, is a condition where the arteries that supply blood to the heart muscle become narrowed or blocked. This narrowing is typically caused by atherosclerosis, a buildup of plaque. CHD is a leading cause of heart attacks and other serious cardiovascular events.
Estimating your risk of developing CHD over the next 10 years is a crucial step in preventive healthcare. This calculator provides an estimate based on several well-established risk factors. Understanding these factors can empower you to make lifestyle changes and work with your doctor to manage your cardiovascular health effectively.
Key Risk Factors Used in This Calculator:
Age: Risk increases significantly with age.
Gender: Historically, men have had a higher risk at younger ages, but women's risk increases substantially after menopause.
Cholesterol Ratio (Total Cholesterol / HDL): A higher ratio indicates more "bad" cholesterol (LDL) relative to "good" cholesterol (HDL), a strong indicator of risk.
Smoking Status: Smoking is a major risk factor, damaging blood vessels and reducing oxygen in the blood.
Diabetes: Diabetes significantly increases the risk of cardiovascular disease due to its effects on blood sugar and blood vessel health.
How the Risk is Calculated (Simplified Explanation)
This calculator uses a simplified model inspired by established risk assessment tools like the Framingham Risk Score. These models assign points or weights to different risk factors. The total score is then converted into a percentage probability of experiencing a CHD event (like a heart attack or death from CHD) within the next 10 years.
The exact formula is complex and often involves logarithmic transformations and specific coefficients derived from large population studies. For instance, a common approach involves calculating a "risk score" based on weighted contributions from each factor:
The specific weights and coefficients vary between different risk models (e.g., Framingham, ASCVD). This calculator provides a general estimate based on these principles.
Interpreting Your Results:
Low Risk: Generally considered less than 10% 10-year risk. Lifestyle modifications are usually recommended.
Moderate Risk: Typically between 10% and 20%. Closer monitoring and potentially medical intervention may be advised.
High Risk: Often considered 20% or higher. Aggressive management of risk factors is crucial.
Disclaimer: This calculator is for informational purposes only. It does not provide medical advice. Always consult with a qualified healthcare professional for diagnosis and treatment recommendations. Your actual risk may differ based on factors not included in this simplified model, such as family history, diet, physical activity levels, and other medical conditions.
function calculateChdRisk() {
var age = parseFloat(document.getElementById("age").value);
var gender = document.getElementById("gender").value;
var systolicBp = parseFloat(document.getElementById("systolicBp").value);
var cholesterolRatio = parseFloat(document.getElementById("cholesterolRatio").value);
var smokingStatus = document.getElementById("smokingStatus").value;
var diabetes = document.getElementById("diabetes").value;
var riskScore = 0;
// — Simplified Risk Factor Weights (Illustrative – actual models are more complex) —
// These weights are conceptual and not precise coefficients from a specific validated score.
// They are designed to demonstrate the principle of how factors contribute.
// Age contribution (increases with age)
if (age >= 40) {
riskScore += (age – 40) * 0.15; // Example weight per year over 40
}
// Gender contribution
if (gender === "male") {
riskScore += 1.0; // Base score for males
} else {
riskScore += 0.7; // Slightly lower base for females (risk catches up later)
}
// Systolic Blood Pressure contribution
if (systolicBp > 120) {
riskScore += (systolicBp – 120) * 0.05; // Example weight per mmHg over 120
}
// Cholesterol Ratio contribution
if (cholesterolRatio > 4.0) {
riskScore += (cholesterolRatio – 4.0) * 1.5; // Example weight per 0.1 ratio over 4.0
}
// Smoking Status contribution
if (smokingStatus === "current-smoker") {
riskScore += 2.5; // Significant addition for current smokers
} else if (smokingStatus === "ex-smoker") {
riskScore += 1.0; // Moderate addition for ex-smokers
}
// Diabetes contribution
if (diabetes === "yes") {
riskScore += 1.8; // Significant addition for diabetics
}
// — Convert Risk Score to 10-Year Risk Percentage —
// This is a highly simplified conversion. Real models use logistic regression.
// We'll use a placeholder formula that generally increases with riskScore.
// A common approach involves exp(score) or similar functions.
// Let's simulate a logistic function's behavior:
var tenYearRiskPercent = 0;
if (riskScore > 0) {
// This is a *highly* simplified approximation of a logistic function's output.
// Real risk scores use specific coefficients and formulas (e.g., Framingham, ASCVD).
// Example: A score of 5 might translate to ~5%, a score of 15 to ~20%, a score of 25 to ~50%
tenYearRiskPercent = 100 * (1 – Math.exp(-Math.exp(riskScore / 10.0))); // Adjusted scaling
}
// Cap the percentage at 100%
tenYearRiskPercent = Math.min(tenYearRiskPercent, 100);
// Display the result
var resultElement = document.getElementById("riskPercentage");
var riskLevelElement = document.getElementById("riskLevel");
// Validate inputs before displaying
if (isNaN(age) || isNaN(systolicBp) || isNaN(cholesterolRatio) ||
age <= 0 || systolicBp <= 0 || cholesterolRatio <= 0) {
resultElement.innerHTML = "Invalid Input";
riskLevelElement.innerHTML = "Please enter valid numbers.";
riskLevelElement.className = ""; // Reset class
return;
}
resultElement.innerHTML = tenYearRiskPercent.toFixed(1) + "%";
// Determine and display risk level
if (tenYearRiskPercent = 10 && tenYearRiskPercent < 20) {
riskLevelElement.innerHTML = "Moderate Risk";
riskLevelElement.className = "moderate-risk";
} else {
riskLevelElement.innerHTML = "High Risk";
riskLevelElement.className = "high-risk";
}
}