LDL test

A blood sample is needed. Most of the time, blood is drawn from a vein located on the inside of the elbow or the back of the hand.

You should not eat for 9 to 12 hours before the test.

Alcohol and some medicines can interfere with blood test results.

• Make sure your health care provider knows what medicines you take, including over-the-counter medicines and supplements.
• Your provider will tell you if you need to stop taking any medicines before you have this test.
• Do not stop or change your medicines without talking to your provider first.

You may feel slight pain or a sting when the needle is inserted. You may also feel some throbbing at the site after the blood is drawn.

LDL cholesterol is usually measured together with other blood fats. Often it is done to help determine your risk of developing heart disease.

High LDL increases your risk for:

• Heart disease
• Peripheral artery disease
• Heart attack
• Stroke

You want your LDL to be low. In general, lower is better.

Your LDL goal is based on your risk for heart disease and whether you have health conditions that increase your risk:

• LDL under 100 mg/dL if you are borderline or moderate risk and do not have diabetes or heart disease (primary prevention)
• LDL under 70 mg/dL if you are at high risk, have diabetes, or have other risk factors (primary prevention)
• LDL under 55 mg/dL if you have had a heart attack or stroke (secondary prevention)

Your provider will help you understand your long-term risk for heart disease and what your LDL goal should be. 

General targets for children are less than 110 mg/dL (2.85 mmol/L) (lower numbers are better).

If your LDL is high and you have certain health risks, your provider will often recommend medicine to lower your LDL cholesterol level.

Normal value ranges may vary slightly among different laboratories. Talk to your provider about the meaning of your specific test results.

A higher-than-normal LDL may be due to:

• Eating a diet high in saturated fats
• Lack of physical activity
• Being overweight or having obesity
• Diabetes
• Metabolic syndrome
• Certain medicines
• Underactive thyroid gland (hypothyroid)
• Disorder passed down through families in which there are high amounts of cholesterol and triglycerides in the blood (familial combined hyperlipidemia)
• Kidney or liver disease

If your LDL level is high, your provider may recommend changes in your lifestyle such as:

• Eating a healthy diet
• Losing weight (if you are overweight or have obesity)
• Getting regular exercise
• Quitting smoking
• Avoiding alcohol

You may also need medicine to lower your LDL levels if you have diabetes or are at risk of heart disease. While taking medicines to lower your LDL level, you should continue the lifestyle changes.

There is little risk involved with having your blood taken. Veins and arteries vary in size from one person to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight, but may include:

• Excessive bleeding
• Fainting or feeling lightheaded
• Multiple punctures to locate veins
• Hematoma (blood buildup under the skin)
• Infection (a slight risk any time the skin is broken)

Certain medicines, pregnancy, infection, and some medical conditions can affect test results.

LDL cholesterol; Low-density lipoprotein LDL cholesterol levels

Blumenthal RS, Morris PB, Gaudino M, et al. 2026 ACC/AHA/AACVPR/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA Guideline on the Management of Dyslipidemia: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. Circulation. 2026 Apr 28;153(17):e1154-e1276. Epub 2026 Mar 13. PMID: 41824552. pubmed.ncbi.nlm.nih.gov/41824552/.

Bredefeld CL, Lau R, Hussain MM. Lipids and dyslipoproteinemia. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 18.

Mora S, Libby P, Ridker PM. Primary prevention of cardiovascular disease. In: Bonow RO, Mann DL, Tomaselli GF, et al, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 13th ed. Philadelphia, PA: Elsevier; 2026:chap 23.

Robinson JG. Disorders of lipid metabolism. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 190.

Tokgözoglu L, Libby P. Lipoprotein disorders and cardiovascular disease. In: Bonow RO, Mann DL, Tomaselli GF, et al, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 13th ed. Philadelphia, PA: Elsevier; 2026:chap 25.

Updated by: Thomas S. Metkus MD, PhD, Associate Professor of Medicine and Surgery, Johns Hopkins University School of Medicine, Baltimore, MD. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.