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Total Cholesterol in Serum

Published: August 9, 2026Updated: August 16, 2026

This test measures the total amount of cholesterol in your blood serum. Cholesterol is a type of fat that your body needs for healthy cells, but high levels can increase your risk of heart disease.

Quick summary

["Knowing your cholesterol helps assess heart health risk and guide lifestyle or treatment changes."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
35987-7
Short code
CT Thigh-L
Synonyms
CT Thigh-L
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ct
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 It Matters in Your Health

Cholesterol plays a vital role in your body’s cells, but too much can build up in your arteries, restricting blood flow and raising the risk of heart disease or stroke. This test helps doctors check if your levels are within a healthy range.

How the Test Works

A small blood sample is drawn, and the cholesterol is measured using a lab technique that detects the total fat content in your serum. Results are reported as a total amount (often in milligrams per deciliter, mg/dL).

What to Expect Before the Test

No special preparation is needed, but you may want to avoid eating a heavy meal 24 hours before the test. If you’re on cholesterol-lowering medications, let your doctor know before scheduling.

What the Results Mean

Your results will be compared to general guidelines (though exact ranges can vary by lab). High levels may prompt discussions about diet, exercise, or medications to lower cholesterol.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Cholesterol and Heart Health

Short name

Cholesterol Level

Frequently asked questions

Why might my doctor order this test?
Your doctor may check cholesterol levels if you have a family history of heart disease, high blood pressure, diabetes, or if you’re over 20 years old (as part of routine cardiovascular screening). It’s also useful for monitoring treatments like diet or medications.
What if my cholesterol is too high?
If your results show high cholesterol, your doctor might recommend lifestyle changes (like eating heart-healthy foods, exercising regularly) or medications to help lower it. Follow-up tests may be needed to track progress.
How often should I get this test?
Most adults are advised to have cholesterol checked every 4–5 years if their levels are normal, or more often if they have risk factors. Your doctor will tailor recommendations based on your health status.
  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 16, 2026. · Read our editorial policy