1. What is the LDL Calculation?

The Friedewald formula estimates LDL cholesterol from total cholesterol, HDL cholesterol, and triglycerides. It's commonly used when direct LDL measurement isn't available.

2. How Does the Calculator Work?

The calculator uses the Friedewald formula:

Where:

• \( LDL \) — Low-density lipoprotein cholesterol (mg/dL)
• \( TC \) — Total cholesterol (mg/dL)
• \( HDL \) — High-density lipoprotein cholesterol (mg/dL)
• \( TG \) — Triglycerides (mg/dL)

Explanation: The formula estimates LDL 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. Monitoring LDL levels helps assess cardiovascular risk and guide treatment decisions.

4. Using the Calculator

Tips: Enter all values in mg/dL from a fasting lipid panel. The formula is most accurate when triglycerides are below 400 mg/dL.

5. Frequently Asked Questions (FAQ)

Q1: When is this calculation not accurate?
A: The formula becomes inaccurate when triglycerides are >400 mg/dL, in non-fasting samples, or with certain genetic lipid disorders.

Q2: What are optimal LDL levels?
A: Optimal is <100 mg/dL, near optimal is 100-129 mg/dL, borderline high is 130-159 mg/dL, high is 160-189 mg/dL, and very high is ≥190 mg/dL.

Q3: Should I fast before the blood test?
A: Yes, a 9-12 hour fast is recommended for accurate triglyceride measurement, which affects LDL calculation.

Q4: Are there alternatives to this calculation?
A: Direct LDL measurement is available and doesn't require fasting, but is more expensive and not always routinely performed.

Q5: How often should LDL be checked?
A: Adults should have a lipid panel every 4-6 years. Those with risk factors may need more frequent testing as recommended by their doctor.