What should you know about an LDL blood test?

LDL is often called “bad” cholesterol because excess LDL can contribute to fatty deposits in artery walls. The result is interpreted with other lipid results, blood pressure, diabetes status, smoking history, family history and any known cardiovascular disease.

The test usually forms part of a lipid panel, which may also report total cholesterol, HDL cholesterol and triglycerides. A higher LDL result can indicate a greater need to review eating patterns, activity, other risk factors and possible treatment. A lower result is not interpreted in isolation either; your clinician considers your overall health and why the test was ordered.

LDL can be affected by recent illness, changes in weight, medicines, thyroid problems, kidney disease and inherited cholesterol conditions. A single result may therefore need context or repeat testing. Ask whether your sample required fasting; preparation instructions vary according to the tests included and your medical history.

Follow the laboratory or clinic instructions about food, drink and medicines before the sample. Do not stop a prescribed medicine unless the clinician who prescribed it tells you to. Keep a record of the full lipid panel and the date of testing, especially if results are being compared over time.

Arrange a results discussion if the report is outside your clinician’s expected range, if you have diabetes, kidney disease or a family history of early heart disease, or if you already take cholesterol-lowering treatment. Practical changes may include replacing saturated fats with unsaturated fats, choosing more fibre-rich foods, staying active within your abilities and avoiding tobacco. The appropriate plan depends on your circumstances.

An LDL result by itself does not usually cause symptoms and is not an emergency. Contact your clinician promptly if you receive a markedly abnormal result, have been told that your cholesterol may be inherited, or are having problems after starting treatment.

Seek emergency help for chest pressure or pain, severe breathlessness, sudden weakness on one side, or sudden trouble speaking. These symptoms need urgent assessment regardless of your LDL result.

Useful questions include: What was my LDL result and how does it compare with my personal target? Do I need a repeat test or a complete lipid panel? Should I change any food, activity or tobacco habits? Could another condition or medicine be affecting the result? Do my family members need cholesterol assessment?