The blood lipids—cholesterol and triglycerides are not soluble in blood. In order for them to be transported through the bloodstream to various tissues, they must be carried in lipoprotein “packages.”

While having low triglycerides and low-density lipoprotein cholesterol is a positive for your heart health, having low levels of high-density lipoprotein (HDL) cholesterol may counteract those benefits because HDL is considered “good cholesterol.” HDL helps to remove LDL cholesterol (your “bad” cholesterol) deposits from the walls of your arteries. This may protect your arteries from clogging up and causing conditions like a heart attack or stroke from coronary artery disease and atherosclerosis.

Studies have shown that low HDL levels are linked to an increased risk of developing cardiovascular disease. This is especially true if other lipids, such as LDL cholesterol and triglycerides, in your blood are also high.

It’s important to understand that there is no direct causal relationship found between HDL levels and having a heart attack or stroke, which means that other factors such as high blood pressure and smoking may play a bigger role.

Causes of Low HDL

There are a number of conditions and lifestyle choices that impact HDL levels.

  • Excess weight: Having excess weight can cause a number of health conditions, including a decrease in your HDL levels.
  • Genetic factors: Sometimes, very low HDL cholesterol levels can be inherited, such as Tangier’s disease and familial hypoalphalipoproteinemia.
  • Poor diet: What you eat can also influence your HDL levels. Limiting saturated fats ( butter, cream, whole or 2 percent milk, beef, pork, chicken with skin) and substituting them for monounsaturated fats like fatty fish, olives, and avocados can increase your HDL.
  • Sedentary lifestyle: Adding moderate exercise to your daily routine may help increase your HDL levels slightly. The American Heart Association recommends aerobic exercising 40 minutes daily three to four times weekly—examples include swimming, brisk walking, running, bicycling, and dancing.
  • Smoking: The chemicals found in cigarettes can lower your HDL cholesterol.
  • Uncontrolled diabetes: Having high blood glucose levels may contribute to lowering HDL cholesterol levels. It can also increase triglyceride and LDL levels.

Total Cholesterol
Optimal : 120 – 199 mg/dL
Borderline high: 200 – 239 mg/dL
High: ≥ 240 mg/dL

LDL Cholesterol
Optimal : < 100 mg/dL
Above optimal: 100 – 129 mg/dL
Borderline high: 130 – 159 mg/dL
High: 160 – 189 mg/dL
Very high: ≥ 190 mg/dL

HDL Cholesterol
Optimal for Men : ≥ 40 mg/dL
Optimal for Women: ≥ 50 mg/dL

Cholesterol: HDL Ratio
Optimal : 3.5:1
Acceptable: < 5:1
High: ≥ 5:1

Non-HDL Cholesterol
Optimal : < 130 mg/dL
Suboptimal: 130 – 159 mg/dL
Borderline high: 160 – 189 mg/dL
High: 190 – 219 mg/dL
Very high: ≥ 220 mg/dL

It is meant to be a measure of all the “bad” cholesterol in the blood

Apolipoprotein B
Optimal : < 90 mg/dL
Suboptimal: 90 – 99 mg/dL
Borderline high: 100 – 119 mg/dL
High: 120 – 139 mg/dL
Very high: ≥ 140 mg/dL

Optimal : < 150 mg/dL
Borderline high: 150 – 199 mg/dL
High: 200 – 499 mg/dL
Very high: ≥ 500 mg/dL