LDL Cholesterol Calculator

Friedewald Formula:

\[ LDL = TC - HDL - \frac{TG}{5} \]

Estimated LDL Cholesterol:

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1. What is the Friedewald Formula?

The Friedewald formula is a widely used equation to estimate LDL cholesterol levels from total cholesterol, HDL cholesterol, and triglyceride measurements. It provides a practical alternative to direct LDL measurement when resources are limited.

2. How Does the Calculator Work?

The calculator uses the Friedewald formula:

\[ LDL = TC - HDL - \frac{TG}{5} \]

Where:

\( TC \) — Total Cholesterol (mg/dL)
\( HDL \) — 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 and greater than 0. Note: This formula is less accurate when triglycerides exceed 400 mg/dL.

5. Frequently Asked Questions (FAQ)

Q1: When is the Friedewald formula not accurate?
A: The formula becomes less accurate when triglyceride levels exceed 400 mg/dL, in non-fasting samples, or in certain medical conditions like dysbetalipoproteinemia.

Q2: What are normal LDL values?
A: Optimal LDL is below 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 and above.

Q3: Should I be fasting for this test?
A: Yes, for accurate results, a 9-12 hour fasting sample is recommended as triglyceride levels can be significantly affected by recent food intake.

Q4: Are there alternative methods for LDL measurement?
A: Yes, direct LDL measurement is available and recommended when triglycerides are high (>400 mg/dL) or when more precise measurement is needed.

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