Total Cholesterol: Normal Range, High & Low Causes
What Total cholesterol measures
Total cholesterol adds together LDL ("bad"), HDL ("good") and a share of your triglycerides. It is a starting point, but the breakdown matters more than the total.
Total cholesterol reference ranges
| Category | Conventional units | SI units |
|---|---|---|
| Desirable | Below 200 mg/dL | Below 5.2 mmol/L |
| Borderline high | 200 – 239 mg/dL | 5.2 – 6.2 mmol/L |
| High | 240 mg/dL or above | 6.2 mmol/L or above |
A high total can come from high HDL, which is not harmful. Always read it alongside LDL, HDL and triglycerides.
Need to convert units? Use the mg/dL ↔ mmol/L converter.
Common causes of a high result
- Diet high in saturated and trans fats
- Inherited high cholesterol (familial hypercholesterolemia)
- Underactive thyroid
- Diabetes, kidney disease or liver disease
- Some medicines, including certain steroids and diuretics
Common causes of a low result
- Very low-fat diets or malnutrition
- Overactive thyroid
- Liver disease or some cancers
- Inherited conditions affecting fat metabolism
How to prepare for the test
A total cholesterol test can usually be done without fasting. Some labs ask for fasting when triglycerides are measured too.
How often to retest
Adults are commonly screened every 4 to 6 years, and more often when risk is higher or treatment is being adjusted.
Track Total cholesterol over time
Upload your reports and Labgist plots every Total cholesterol result on one timeline, converts units and shows what changed.
Get the appFrequently asked questions
What is a good total cholesterol number?
Below 200 mg/dL (5.2 mmol/L) is desirable for most adults, but your LDL, HDL and overall heart risk decide what is right for you.
Do I need to fast for a cholesterol test?
Often not. Many labs accept non-fasting samples, but follow the instructions you are given, especially if triglycerides are included.
Why is my total cholesterol high but my doctor is not worried?
A high HDL can raise the total without raising risk. Clinicians look at LDL, HDL, triglycerides and other risk factors together.
Related tests
Sources
This page is general education and was last updated 2026-10-30. It is not a substitute for medical advice. See our editorial approach.