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Total Testosterone (Serum/Plasma)

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

This test measures the amount of total testosterone, a key male sex hormone, in your blood. It helps assess hormone levels related to reproductive health, muscle mass, and overall well-being.

Quick summary

["Your testosterone levels can influence energy, mood, and fertility."]

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

Key facts at a glance

LOINC
58716-2
Short code
Testost free+WB + Total pnl SerPl
Synonyms
Testost free+WB + Total pnl SerPl
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
44
Ref high
147
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
84075
SNOMED
27550007
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 Is Done

Doctors may order a total testosterone test to evaluate symptoms like low energy, reduced sex drive, infertility, or unexplained muscle loss. It’s also used in diagnosing conditions such as hypogonadism (low testosterone) or evaluating hormone-related disorders, including those affecting men and women.

What to Expect Before the Test

No special preparation is needed, but you may be asked to fast for 8–12 hours before drawing blood. If you’re taking medications that affect hormone levels, let your provider know. Avoid alcohol for 24 hours before testing.

What Happens During the Test

A healthcare provider will collect a blood sample from a vein in your arm. The sample is sent to a lab for analysis. The test typically takes a few minutes, and you can resume normal activities afterward.

What the Results Mean

Results are compared to general reference ranges, but individual needs vary. Low testosterone may indicate hormonal imbalances, while very high levels could signal conditions like Cushing’s syndrome or tumors. Your doctor will interpret results in the context of your symptoms and medical history.

Reference range

Adult: 44-147 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.

◆Associated findings1

Short name

Total Testosterone

Frequently asked questions

What causes low testosterone?
Low testosterone can result from aging, chronic illnesses (like diabetes or kidney disease), medications (e.g., steroids), obesity, or hormonal imbalances. Lifestyle factors such as poor sleep, excessive alcohol use, or smoking may also play a role.
What causes high testosterone?
High testosterone is less common but can occur due to tumors (benign or malignant), genetic conditions, or hormonal disorders like Cushing’s syndrome. In women, high levels may be linked to polycystic ovary syndrome (PCOS) or androgen-secreting tumors.
How often should I get this test?
Frequency depends on your symptoms, age, and medical history. For men over 40, routine checks may be recommended every 1–2 years. If you have a known condition affecting testosterone, your doctor may schedule tests more often.
  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