CARDIOVASCULAR & LIPIDS

Why you should care: Total cholesterol is the sum of all cholesterol in your blood. It is the starting point, but it is a blunt tool. Someone with high HDL (“good” cholesterol) could have an elevated total number while actually being at lower risk. It is most useful as part of ratios and calculations — not on its own.

Target range: Below 200 mg/dL is considered desirable. 200-239 is borderline high. 240+ is high.

What pushes it up or down:

• Higher: Diets high in saturated/trans fats, genetics, hypothyroidism, liver disease
• Lower: Statin therapy, hyperthyroidism, malnutrition

Why you should care: LDL is the single most important number for predicting plaque buildup in your arteries. It is the type of cholesterol that penetrates artery walls and drives heart disease. Large-scale research has consistently shown that lowering LDL reduces cardiovascular events. Every 39 mg/dL reduction is associated with roughly a 22% drop in major heart events.

Target range: Most guidelines target LDL below 100 mg/dL for the general population and below 70 mg/dL for people with existing heart disease or high risk. Some European guidelines push even lower — below 55 mg/dL for very high-risk patients.

What pushes it up or down:

• Higher: Saturated/trans fat intake, genetics (familial high cholesterol affects ~1 in 250 people), obesity, diabetes, hypothyroidism
• Lower: Statins, ezetimibe, PCSK9 inhibitors, weight loss, dietary changes

Why you should care: HDL is the “cleanup crew.” It picks up cholesterol from your artery walls and carries it back to the liver for disposal. Higher levels have been consistently linked to lower heart disease risk. But here is the catch: drugs that artificially raise HDL have failed to reduce heart attacks in clinical trials. That means HDL is a useful indicator of health, but forcing it higher with medication does not help. How well your HDL particles function may matter more than the raw number.

Target range: Below 40 mg/dL in men or below 50 mg/dL in women is considered a risk factor. There is no specific upper target — higher is generally better.

What pushes it up or down:

• Higher: Regular exercise, moderate alcohol, weight loss
• Lower: Smoking, inactivity, obesity, type 2 diabetes, very-high-carb diets

Why you should care: Triglycerides are the most common fat in your blood. Your body converts excess calories — especially from carbs and alcohol — into triglycerides. Elevated triglycerides are one of the strongest blood markers of insulin resistance and metabolic problems. Very high levels (above 500 mg/dL) also carry risk for pancreatitis.

Target range: Below 150 mg/dL is normal. 150-199 is borderline high. 200-499 is high. 500+ is very high and needs attention.

What pushes it up or down:

• Higher: Excess calories (especially refined carbs and sugar), alcohol, inactivity, obesity, poorly controlled diabetes, certain medications
• Lower: Weight loss, reduced carb intake, exercise, omega-3 fatty acids, fibrate medications
• Note: Whether you fasted matters — non-fasting samples run higher

Why you should care: Non-HDL is simply total cholesterol minus HDL. It captures all the cholesterol in particles that can build up in your arteries — not just LDL, but also VLDL and other leftover fat particles. Research shows it is actually a stronger predictor of heart events than LDL alone. It is especially useful if your triglycerides are elevated, because in that case LDL alone can underestimate your real risk.

Target range: Generally 30 mg/dL above whatever LDL target applies to you. For most people, below 130 mg/dL. For high-risk patients, below 100 mg/dL.

What pushes it up or down:

• Same factors as LDL and triglycerides. Elevated triglycerides in particular can drive non-HDL high even when LDL looks normal.

Why you should care: ApoB is arguably the most important number on an advanced lipid panel. Every cholesterol particle that can build plaque in your arteries carries exactly one ApoB molecule. So measuring ApoB gives you a direct count of how many dangerous particles are circulating in your blood.

Here is why that matters: two people can have the same LDL number but very different numbers of particles. If you have many small, cholesterol-depleted particles, your LDL looks “normal” but your actual particle count (ApoB) is high — and your risk tracks with the particle count. Growing expert consensus now considers ApoB superior to LDL for assessing risk.

Target range: Below 90 mg/dL for moderate risk. Below 80 mg/dL for high risk. Below 65 mg/dL for very high risk.

What pushes it up or down:

• Higher: Saturated fat, genetics, insulin resistance, obesity, diabetes — notably, insulin resistance can raise ApoB even when LDL stays normal
• Lower: Statins, PCSK9 inhibitors, ezetimibe, weight loss, dietary changes

Why you should care: Lp(a) is a genetic wildcard. Your level is almost entirely determined by your DNA and stays stable your whole life. About 20% of the population has elevated Lp(a), making it a hidden risk factor that would never show up on a standard lipid panel. Elevated Lp(a) independently increases risk for heart disease and aortic valve problems.

The hard part: diet, exercise, and most cholesterol medications (including statins) do not lower it. PCSK9 inhibitors reduce it modestly (20-30%), and dedicated Lp(a)-lowering drugs are in late-stage clinical trials. Current guidelines recommend measuring Lp(a) at least once in your lifetime.

Target range: Below 50 mg/dL (or ~125 nmol/L). Levels above this are considered a risk-enhancing factor.

What pushes it up or down:

• Primarily genetic — lifestyle changes have minimal effect
• PCSK9 inhibitors provide moderate reduction
• Kidney disease and hypothyroidism can modestly affect levels