1. What is the Friedewald Equation?

The Friedewald equation is a formula used to estimate LDL cholesterol (LDL-C) levels from measurements of total cholesterol, HDL cholesterol, and triglycerides. It provides a calculated LDL value without requiring direct measurement, which is more expensive and time-consuming.

2. How Does the Calculator Work?

The calculator uses the Friedewald equation:

Where:

• \( TC \) — Total cholesterol (mg/dL)
• \( HDL-C \) — HDL cholesterol (mg/dL)
• \( TG \) — Triglycerides (mg/dL)

Explanation: The equation estimates LDL cholesterol by subtracting HDL cholesterol and VLDL cholesterol (estimated as TG/5) from total cholesterol.

3. Interpretation of High LDL-C Results

Details: High calculated LDL cholesterol (typically >160 mg/dL) indicates increased risk for cardiovascular disease. It suggests excess cholesterol is circulating in the blood, which can lead to plaque formation in arteries.

4. Using the Calculator

Tips: Enter total cholesterol, HDL cholesterol, and triglycerides in mg/dL. All values must be valid (greater than 0). Note that the equation becomes less accurate when triglyceride levels exceed 400 mg/dL.

5. Frequently Asked Questions (FAQ)

Q1: Why might calculated LDL be high?
A: High calculated LDL typically indicates dyslipidemia, which can result from genetic factors, diet high in saturated fats, lack of exercise, or certain medical conditions.

Q2: What are the limitations of the Friedewald equation?
A: The equation becomes less accurate when triglyceride levels exceed 400 mg/dL, in non-fasting samples, or in patients with certain metabolic disorders.

Q3: How does high LDL affect health?
A: Elevated LDL cholesterol is a major risk factor for atherosclerosis, coronary artery disease, heart attack, and stroke.

Q4: When should direct LDL measurement be used instead?
A: Direct measurement is recommended when triglycerides are >400 mg/dL, in patients with diabetes, or when very precise LDL measurement is needed.

Q5: What are the treatment options for high LDL?
A: Lifestyle modifications (diet, exercise) are first-line treatment, followed by medications like statins if needed. Treatment goals depend on individual risk factors.