1. What is the LDL Cholesterol Formula?

The Friedewald formula calculates LDL cholesterol from total cholesterol, HDL cholesterol, and triglyceride measurements. It's a widely used method for estimating LDL levels when direct 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)

Note: This formula is valid only when triglycerides are less than 400 mg/dL. For higher triglyceride levels, direct LDL measurement is recommended.

3. Importance of LDL Calculation

Details: LDL cholesterol is often called "bad cholesterol" because high levels can lead to plaque buildup in arteries and increase risk of heart disease and stroke. Monitoring LDL levels is crucial for cardiovascular risk assessment and management.

4. Using the Calculator

Tips: Enter total cholesterol, HDL cholesterol, and triglycerides in mg/dL. All values must be valid positive numbers. For accurate results, ensure triglyceride levels are below 400 mg/dL.

5. Frequently Asked Questions (FAQ)

Q1: Why divide triglycerides by 5 in the formula?
A: The division by 5 is based on the average ratio of very-low-density lipoprotein (VLDL) cholesterol to triglycerides, which is approximately 1:5.

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

Q3: When is this formula not accurate?
A: The formula is less accurate when triglycerides exceed 400 mg/dL, in non-fasting samples, or in patients with certain conditions like diabetes or very high cholesterol.

Q4: How often should LDL be checked?
A: Adults should have cholesterol checked every 4-6 years. Those with risk factors may need more frequent testing as recommended by their healthcare provider.

Q5: Can lifestyle changes affect LDL levels?
A: Yes, diet, exercise, weight management, and smoking cessation can significantly impact LDL cholesterol levels.