1. What Is LDL Calculated Qn?

The Friedewald formula calculates LDL cholesterol (LDL-C) from total cholesterol (TC), HDL cholesterol (HDL-C), and triglycerides (TG). It provides an estimated LDL value without requiring direct measurement, making it a widely used method in clinical practice.

2. How Does the Calculator Work?

The calculator uses the Friedewald formula:

Where:

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

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

3. Importance of LDL Calculation

Details: LDL cholesterol is a major risk factor for cardiovascular disease. Accurate estimation helps in assessing cardiovascular risk and guiding treatment decisions for cholesterol management.

4. Using the Calculator

Tips: Enter total cholesterol, HDL cholesterol, and triglycerides in mg/dL. All values must be valid (TC > 0, HDL-C ≥ 0, TG ≥ 0). Note: This formula is not accurate when TG > 400 mg/dL.

5. Frequently Asked Questions (FAQ)

Q1: Why use the Friedewald formula?
A: It provides a quick and cost-effective way to estimate LDL cholesterol without direct measurement, making it useful for routine screening.

Q2: What are normal LDL values?
A: Optimal LDL is <100 mg/dL. Near optimal is 100-129 mg/dL. Borderline high is 130-159 mg/dL. High is 160-189 mg/dL. Very high is ≥190 mg/dL.

Q3: When should direct LDL measurement be used?
A: Direct measurement is recommended when triglycerides are >400 mg/dL, in non-fasting samples, or when more precise LDL measurement is needed.

Q4: Are there limitations to this formula?
A: Less accurate with high triglycerides (>400 mg/dL), in non-fasting states, and in certain conditions like diabetes or very low LDL levels.

Q5: How often should LDL be checked?
A: Adults should have cholesterol checked every 4-6 years. More frequent testing may be needed for those with risk factors or on cholesterol-lowering treatment.