Order Code
2830
Preferred Specimen
Collect 2 mL of serum using an SST tube. Allow the blood to clot in an upright position for a minimum of 30 minutes, then centrifuge the sample within 2 hours of collection. Refrigerate promptly.
Note: Samples should not be collected from patients receiving nandrolone treatment, as certain synthetic androgens may not be detected by this assay. For women and children, an ultrasensitive testosterone test is recommended.
ContainerType
Serum separator tube
Alternate Specimen Requirements
Collect 2 mL of serum in a plain red top tube. Let the sample clot upright for at least 60 minutes, then centrifuge and transfer serum to a plastic transport tube within 2 hours of collection. Clearly label the tube as serum from a plain red top tube. Refrigerate.
Note: Avoid sample collection in patients on nandrolone therapy, as the assay may not detect all synthetic androgens. Ultrasensitive testosterone testing should be considered for females and pediatric patients.
Minimum Volume
Adult: 1 mL serum
Pediatric: 0.2 mL serum (does not allow for repeat or
additional testing).
Transport Temperature
Refrigerated
Expected Turnaround Time
2 days
Specimen Stability
1 day room temperature; 1 week refrigerated; 1 month frozen
Methodology
Roche COBAS Electrochemiluminescent Immunoassay (ECLIA)
Rejection Criteria
- Gross hemolysis
heat-inactivated samples
avoid repeated freeze/thaw cycles
Overview
Testosterone, a steroid hormone derived from cholesterol, is regulated by the hypothalamic-pituitary-gonadal (HPG) axis through a classic negative feedback mechanism. When testosterone levels decrease, the hypothalamus releases gonadotropin-releasing hormone (GnRH), stimulating the anterior pituitary to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH). In males, FSH promotes spermatogenesis, while LH stimulates testosterone production by the testes. Testosterone secretion follows a circadian rhythm, peaking around 6 AM and reaching its lowest levels near 6 PM.
Functioning both as an androgen and a prohormone, testosterone can be converted into dihydrotestosterone (DHT), a more potent androgen, and into estradiol, an estrogenic hormone. In males, testosterone and DHT play key roles in the development of external genitalia and secondary sexual characteristics. In females, testosterone mainly serves as a precursor to estrogen.
In circulation, testosterone exists as free (active) hormone (~<5%), loosely bound to albumin (~30%), or tightly bound to sex hormone-binding globulin (SHBG) (~65%). Total testosterone measurement, widely accessible and cost-effective, is commonly used to evaluate hypogonadism in men. However, interpretation may be complicated by variations in SHBG levels, as SHBG-bound testosterone is biologically unavailable. Conditions that elevate SHBG (such as hyperthyroidism, increased estrogen levels, and aging) can reduce bioavailable testosterone, potentially leading to underdiagnosis of hypogonadism based on total testosterone alone.
Clinical Significance
- Total testosterone is usually adequate in the evaluation of adult males
- Evaluate symptoms of male hypogonadism (eg, erectile dysfunction, lowered sperm count, gynecomastia, change in mood, osteopenia or osteoporosis, decreased muscle mass, shrunken or softened testes)
- Evaluate male infertility to distinguish primary hypogonadism (low total testosterone, increased blood LH, FSH; infertile) from secondary hypogonadism (low total testosterone, low to low-normal blood LH, FSH; potentially fertile)
- Evaluate for suspected androgen-secreting tumor
- Monitor total testosterone therapy in males to ensure normal testosterone concentrations are achieved
- Monitor antiandrogen testosterone deprivation therapy in males (eg, treatment of prostate cancer)
- Not the preferred test to evaluate testosterone levels in children and females as the small amount of testosterone present may not be accurately quantified
Additional Information
In men, testosterone is primarily secreted by the testes. In women, about 25% is produced by the adrenal glands, 25% by the ovaries, and the remaining 50% results from peripheral conversion of androstenedione.
Testosterone influences multiple physiological functions in men, including maintenance of reproductive tissues, spermatogenesis, sexual function, lean muscle mass, bone density, body hair growth, and red blood cell production. A 2007 study reported a 5.6% prevalence of symptomatic testosterone deficiency among U.S. men aged 30 to 79 years.
There are no universally accepted guidelines for diagnosing low testosterone; however, a consensus from several international societies suggests the following:
- Total testosterone > 350 ng/dL: No treatment indicated
- Total testosterone 230–350 ng/dL: Repeat total testosterone and measure SHBG to calculate free testosterone
- Total testosterone < 230 ng/dL: Consider testosterone replacement therapy
Conditions associated with abnormal testosterone levels include:
- Polycystic Ovary Syndrome (PCOS), characterized by androgen excess symptoms such as anovulation, hirsutism, acne, and male-pattern baldness
- Androgen Insensitivity Syndrome (AIS), where a 46XY fetus has mutations affecting androgen receptor function, resulting in a female phenotype
- Klinefelter Syndrome (47XXY), presenting with low or low-normal testosterone, reduced muscle mass, decreased body hair, gynecomastia, and impaired spermatogenesis
Testosterone replacement therapy requires monitoring for potential adverse effects including lipid abnormalities, increased cardiovascular risk, exacerbation of sleep apnea, polycythemia, and possible prostate cancer progression. Regular follow-up and testosterone level assessments are essential to optimize treatment and minimize side effects.
Interpretative Information
Male
- Decreased
- Primary hypogonadism due to testes dysfunction (elevated LH, FSH levels), including trauma, castration, aging, Klinefelter syndrome, autoimmune conditions, infection, drugs (alcohol, ketoconazole)
- Secondary hypogonadism due to hypothalamic or pituitary dysfunction (low or low-normal LH, FSH levels), including primary pituitary/hypothalamic failure, tumors or infiltrating diseases of pituitary/hypothalamus, hemochromatosis, Kallman syndrome, HIV infection, aging, drugs (opioids, estrogens, steroids, GnRH agonists)
- Elevated
- Testicular tumors
- Adrenal tumors
- Exogenous testosterone use
- Hyperthyroidism
- Congenital adrenal hyperplasia
- Androgen resistance
Female
- Decreased
- Primary or secondary ovarian failure
- Oophorectomy
- Increased
- Polycystic ovary syndrome
- Ovary or adrenal tumor
- Congenital adrenocortical hyperplasia
Limitations
- No universally accepted testosterone-calibration laboratory standard in the United States (Rosner 2007).
- Assay-to-assay variability in reported total testosterone values may be extreme (Matsumoto 2008).
- Assay ranges for serum testosterone are based on studies which primarily included men greater than 65 years old and were not were designed to establish normal ranges in men with normal reproductive and sexual function. In addition, age, ethnicity and gender-adjusted ranges of serum testosterone have not been established (Paduch 2014).
- Testosterone levels show considerable day-to-day variability within individual men. A minimum of two morning values should be obtained during evaluation for hypogonadism (Matsumoto 2008).
- Serum testosterone levels may be affected by acute illness, extreme exercise, or certain medications (CNS-active medications, opioids, or glucocorticoids) which temporarily decrease testosterone. Suppression of testosterone is particularly affected by methadone due to its long half-life (Paduch 2014).
- Nutritional deficiency (starvation or eating disorder) may increase SHBG levels (Matsumoto 2008).
- Use of certain steroids makes interpretation of testosterone levels problematic due to similar chemical structures interfering with assay results (Paduch 2014).
References
Allan CA, McLachlan RI. Age-related changes in testosterone and the role of replacement therapy in older men. Clin Endocrinol (Oxf). 2004;60(6):653-670.15163327
Araujo AB, Esche GR, Kupelian V et al. Prevalence of symptomatic androgen deficiency in men. J Clin Endocrinol Metab. 2007;92(11):4241-4247.17698901
Ashok S, Sigman M. Bioavailable testosterone should be used for the determination of androgen levels in infertile men. J Urol. 2007;177(4):1443-1446.17382750
Carnegie C. Diagnosis of hypogonadism: clinical assessments and laboratory tests. Rev Urol. 2004;6 Suppl 6:S3-8.16985909
Dandona P, Rosenberg MT. A practical guide to male hypogonadism in the primary care setting. Int J Clin Pract. 2010;64(6):682-696.20518947
Freeman ER, Bloom DA, McGuire EJ. A brief history of testosterone. J Urol. 2001;165(2):371-373.11176375
Manni A, Pardridge WM, Cefalu W, et al. Bioavailability of albumin-bound testosterone. J Clin Endocrinol Metab. 1985;61(4):705-710.4040924
Matsumoto AM. Diagnosis and Evaluation of Male Hypogonadism. Medscape website http://www.medscape.org/viewarticle/575491. Published June 27, 2008. Accessed April 29, 2015.
Ohl DA, Quallich SA. Clinical hypogonadism and androgen replacement therapy: an overview. Urol Nurs. 2006;26(4):253-259.16939042
Paduch DA, Brannigan RE, Fuchs EF, Kim ED, Marmar JL, Sandlow JI. The laboratory diagnosis of testosterone deficiency. Urology. 2014;83(5):980-988.24548716
Petak SM, Nankin HR, Spark RF, Swerdloff RS, Rodriguez-Rigau LJ; American Association of Clinical Endocrinologists. American Association of Clinical Endocrinologists Medical Guidelines for clinical practice for the evaluation and treatment of hypogonadism in adult male patients–2002 update. Endocr Pract. 2002;8(6):440-456.15260010
Purifoy FE, Koopmans LH, Mayes DM. Age differences in serum androgen levels in normal adult males. Hum Biol. 1981;53(4):499-511.7199020
Rhoden EL, Morgentaler A. Risks of testosterone-replacement therapy and recommendations for monitoring. N Engl J Med. 2004;350(5):482-492.14749457
Rosner W, Auchus RJ, Azziz R, Sluss PM, Raff H. Position statement: Utility, limitations, and pitfalls in measuring testosterone: an Endocrine Society position statement. J Clin Endocrinol Metab. 2007;92(2):405-413.17090633
Shores MM, Smith NL, Forsberg CW, Anawalt BD, Matsumoto AM. Testosterone treatment and mortality in men with low testosterone levels. J Clin Endocrinol Metab. 2012;97(6):2050-2058.22496507
Southren AL, Gordon GG, Tochimoto S, Pinzon G, Lane DR, Stypulkowski W. Mean plasma concentration, metabolic clearance and basal plasma production rates of testosterone in normal young men and women using a constant infusion procedure: effect of time of day and plasma concentration on the metabolic clearance rate of testosterone. J Clin Endocrinol Metab. 1967;27(5):686-694.6025472
Swerdloff RS, Wang C. The testis and male sexual function. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 242.
Wu AHB, ed. Tietz Clinical Guide to Laboratory Tests. 4th ed. St. Louis, MO: WB Saunders/Elsevier; 2006.
Diagnostic Role
Testosterone levels are ordered to evaluate signs or symptoms of abnormal androgen production. This includes early or delayed puberty in boys; erectile dysfunction or infertility in adult males; and virilization symptoms in females, such as hirsutism, irregular or absent menses, or male-pattern baldness.
Total testosterone is most commonly ordered in the evaluation of suspected hypogonadism in adult males, and should be collected between 6 AM (0600) and 10 AM (1000) (preferably 0600 to 0800) when the level is at its highest. This test is readily available in most laboratories, inexpensive, and is usually sufficient to distinguish eugonadal from hypogonadal states in the adult male (Matsumoto 2008). LH and FSH levels may be concurrently obtained to help distinguish primary hypogonadism (low testosterone, high LH and FSH) from secondary hypogonadism (low testosterone, low to low-normal LH and FSH).
There is no universally accepted threshold of testosterone concentration that distinguishes eugonadal from hypogonadal men; laboratory results have to be interpreted in the appropriate clinical setting (Paduch 2014). When the total testosterone lies near the lower limit of the normal range, however, a calculated free testosterone level may be useful in clarifying the diagnosis (Rosner 2007).
Alias
- Serum testosterone
- testosterone, total, serum
- total testosterone, serum
Test Setup Days
Monday through Friday PM shift
CPT
84403 LOINC: 2986-8
Reference Range
MALE FEMALE
AGE 0-1 MONTH: 75-400 NG/DL 20-64 NG/DL
2-5 MONTHS: 14-363 NG/DL <20 NG/DL
6-24 MONTHS: <37 NG/DL <12 NG/DL
2-3 YEARS: <15 NG/DL <20 NG/DL
4-5 YEARS: <19 NG/DL <30 NG/DL
6-7 YEARS: <13 NG/DL <12 NG/DL
8-9 YEARS: <12 NG/DL <12 NG/DL
10-11 YEARS: <165 NG/DL <32 NG/DL
12-13 YEARS: <619 NG/DL <50 NG/DL
14-15 YEARS: 31-733 NG/DL <52 NG/DL
16-17 YEARS: 158-826 NG/DL <58 NG/DL
18-39 YEARS: 300-1080 NG/DL <=55 NG/DL
40-59 YEARS: 300-890 NG/DL <=55 NG/DL
>59 YEARS: 300-720 NG/DL <=32 NG/DL
FOR PATIENTS BETWEEN 10-17 YEARS:
TANNER I <15 NG/DL <17 NG/DL
TANNER II <303 NG/DL <40 NG/DL
TANNER III <851 NG/DL <63 NG/DL
TANNER IV 165-854 NG/DL <62 NG/DL
TANNER V 194-783 NG/DL <62 NG/DL
| UNIT CODE | UNIT CODE NAME | ANALYTE | GENDER | AGE | REFERENCE RANGE | Units of Measure |
|---|---|---|---|---|---|---|
| 2830 | TESTOST | TESTOS | NOT SPECIFIED | 0Y | <720 | NG/DL |
| 2830 | TESTOST | TESTOS | NOT SPECIFIED | 29D | 20-400 | NG/DL |
| 2830 | TESTOST | TESTOS | NOT SPECIFIED | 5M | <363 | NG/DL |
| 2830 | TESTOST | TESTOS | NOT SPECIFIED | 2Y | <37 | NG/DL |
| 2830 | TESTOST | TESTOS | NOT SPECIFIED | 3Y | <20 | NG/DL |
| 2830 | TESTOST | TESTOS | NOT SPECIFIED | 5Y | <30 | NG/DL |
| 2830 | TESTOST | TESTOS | NOT SPECIFIED | 7Y | <13 | NG/DL |
| 2830 | TESTOST | TESTOS | NOT SPECIFIED | 9Y | <12 | NG/DL |
| 2830 | TESTOST | TESTOS | NOT SPECIFIED | 11Y | <165 | NG/DL |
| 2830 | TESTOST | TESTOS | NOT SPECIFIED | 13Y | <619 | NG/DL |
| 2830 | TESTOST | TESTOS | NOT SPECIFIED | 15Y | <733 | NG/DL |
| 2830 | TESTOST | TESTOS | NOT SPECIFIED | 17Y | <826 | NG/DL |
| 2830 | TESTOST | TESTOS | NOT SPECIFIED | 39Y | SEE BELOW | NG/DL |
| 2830 | TESTOST | TESTOS | NOT SPECIFIED | 59Y | SEE BELOW | NG/DL |
| 2830 | TESTOST | TESTOS | NOT SPECIFIED | 150Y | SEE BELOW | NG/DL |
| 2830 | TESTOST | TESTOS | MALE | 0Y | 300-720 | NG/DL |
| 2830 | TESTOST | TESTOS | MALE | 29D | 75-400 | NG/DL |
| 2830 | TESTOST | TESTOS | MALE | 5M | 14-363 | NG/DL |
| 2830 | TESTOST | TESTOS | MALE | 2Y | <37 | NG/DL |
| 2830 | TESTOST | TESTOS | MALE | 3Y | <15 | NG/DL |
| 2830 | TESTOST | TESTOS | MALE | 5Y | <19 | NG/DL |
| 2830 | TESTOST | TESTOS | MALE | 7Y | <13 | NG/DL |
| 2830 | TESTOST | TESTOS | MALE | 9Y | <12 | NG/DL |
| 2830 | TESTOST | TESTOS | MALE | 11Y | <165 | NG/DL |
| 2830 | TESTOST | TESTOS | MALE | 13Y | <619 | NG/DL |
| 2830 | TESTOST | TESTOS | MALE | 15Y | 31-733 | NG/DL |
| 2830 | TESTOST | TESTOS | MALE | 17Y | 158-826 | NG/DL |
| 2830 | TESTOST | TESTOS | MALE | 39Y | 300-1080 | NG/DL |
| 2830 | TESTOST | TESTOS | MALE | 59Y | 300-890 | NG/DL |
| 2830 | TESTOST | TESTOS | MALE | 150Y | 300-720 | NG/DL |
| 2830 | TESTOST | TESTOS | FEMALE | 0Y | <=32 | NG/DL |
| 2830 | TESTOST | TESTOS | FEMALE | 29D | 20-64 | NG/DL |
| 2830 | TESTOST | TESTOS | FEMALE | 5M | <20 | NG/DL |
| 2830 | TESTOST | TESTOS | FEMALE | 2Y | <12 | NG/DL |
| 2830 | TESTOST | TESTOS | FEMALE | 3Y | <20 | NG/DL |
| 2830 | TESTOST | TESTOS | FEMALE | 5Y | <30 | NG/DL |
| 2830 | TESTOST | TESTOS | FEMALE | 7Y | <12 | NG/DL |
| 2830 | TESTOST | TESTOS | FEMALE | 9Y | <12 | NG/DL |
| 2830 | TESTOST | TESTOS | FEMALE | 11Y | <32 | NG/DL |
| 2830 | TESTOST | TESTOS | FEMALE | 13Y | <50 | NG/DL |
| 2830 | TESTOST | TESTOS | FEMALE | 15Y | <52 | NG/DL |
| 2830 | TESTOST | TESTOS | FEMALE | 17Y | <58 | NG/DL |
| 2830 | TESTOST | TESTOS | FEMALE | 39Y | <=55 | NG/DL |
| 2830 | TESTOST | TESTOS | FEMALE | 59Y | <=55 | NG/DL |
| 2830 | TESTOST | TESTOS | FEMALE | 150Y | <=32 | NG/DL |