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Cholesterol (Total) in Serum or Plasma

Published: August 9, 2026Updated: August 17, 2026

This test measures the total amount of cholesterol in your blood, which includes both the cholesterol your body makes and the cholesterol you get from foods.

Quick summary

["Cholesterol levels help assess heart health and risk of cardiovascular disease."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
29324-1
Short code
Cocaethylene Gast-mCnc
Synonyms
Cocaethylene Gast-mCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
10
Ref high
40
Critical range
— – 500 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
84484
SNOMED
302774002
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why This Test Matters

Cholesterol is a type of fat that your body needs for healthy cells, but having too much can build up in your arteries, increasing your risk of heart problems. This test helps doctors monitor your cholesterol levels to guide lifestyle and treatment recommendations.

What to Expect Before the Test

No special preparation is needed, but you may be asked to fast for 12 hours before the test if your doctor requests it. Bring any medications you’re currently taking, as some can affect cholesterol levels.

How the Test Works

A blood sample is drawn from a vein, usually in your arm. The sample is sent to a lab where it is analyzed to measure the total cholesterol concentration in your blood plasma or serum.

What the Results Mean

Results are typically reported in milligrams per deciliter (mg/dL). While specific ranges vary by lab, higher-than-normal levels may signal a need for dietary changes, exercise, or medication to improve heart health.

Reference range

Adult: 10-40 U/LN/A

Specimen: serum

No special preparation required. Avoid fatty meals before the test if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Elevated cholesterol levels are a key risk factor for atherosclerosis (plaque buildup in arteries), which can lead to heart attacks or strokes. Regular monitoring helps manage this risk, especially if you have a family history of high cholesterol or other cardiovascular conditions.

Short name

Total Cholesterol

Frequently asked questions

What causes high cholesterol?
High cholesterol can result from genetics, an unhealthy diet (high in saturated fats), lack of physical activity, obesity, or certain medical conditions like diabetes. Lifestyle changes, such as eating heart-healthy foods and exercising regularly, can help lower cholesterol naturally.
How often should I get this test?
Your doctor will determine how often you need this test based on your age, risk factors, and overall health. Typically, adults with no risk factors may get tested every 5 years, while those with risk factors (like high blood pressure or a family history of heart disease) may need testing more frequently.
Can diet or exercise change my cholesterol results?
Yes! Adopting a diet low in saturated and trans fats, increasing fiber intake (like from fruits, vegetables, and whole grains), and engaging in regular physical activity can significantly lower cholesterol levels. Small, sustainable changes often yield the best results.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy