Synonym/Acronym
N/A
Rationale
To evaluate testosterone to assist in identification of disorders related to early puberty, late puberty, and infertility while assessing gonadal and adrenal function.
Patient Preparation
There are no food, fluid, activity, or medication restrictions unless by medical direction.
Normal Findings
Method: HPLC/tandem MS for total testosterone and equilibrium dialysis for free testosterone.
Total Testosterone
| Age | Conventional Units | SI Units (Conventional Units × 0.0347) |
|---|
| Newborn | | | | Male | 75–400 ng/dL | 2.6–13.9 nmol/L | | Female | 16–64 ng/dL | 0.56–2.22 nmol/L | | 1–5 mo | | | | Male | Less than 360 ng/dL | Less than 12.49 nmol/L | | Female | Less than 20 ng/dL | Less than 0.69 nmol/L | | 6–11 mo | | | | Male | Less than 40 ng/dL | Less than 1.39 nmol/L | | Female | Less than 9 ng/dL | Less than 0.31 nmol/L | | 1–5 yr | | | | Male and female | Less than 20 ng/dL | Less than 0.69 nmol/L | | 6–7 yr | | | | Male | Less than 20 ng/dL | Less than 0.69 nmol/L | | Female | Less than 7 ng/dL | Less than 0.24 nmol/L | | 8–11 yr | | | | Male | 2–165 ng/dL | 0.07–5.72 nmol/L | | Female | 1–30 ng/dL | 0.04–1 nmol/L | | 12–13 yr | | | | Male | Less than 600 ng/dL | Less than 20.8 nmol/L | | Female | Less than 50 ng/dL | Less than 1.74 nmol/L | | 14–15 yr | | | | Male | 15–700 ng/dL | 0.52–24.29 nmol/L | | Female | Less than 60 ng/dL | Less than 2.08 nmol/L | | Adult | | | | Male | 300–1080 ng/dL | 10.41–37.48 nmol/L | | Female | 10–60 ng/dL | 0.35–2.08 nmol/L | | Older adult | | | | Male | 300–720 ng/dL | 10.41–24.98 | | Female | 5–32 ng/dL | 0.17–1.11 |
Postmenopausal levels are about half the normal adult level for females; levels in women who are pregnant are three to four times the normal adult level for females who are not pregnant. |
Free Testosterone
| Age | Conventional Units | SI Units (Conventional Units × 3.47) |
|---|
| 7 mo–9 yr | | | | Male and female | Less than 2 pg/mL | Less than 7 pmol/L | | 10–11 yr | | | | Male | Less than 7 pg/mL | Less than 25 pmol/L | | Female | Less than 4 pg/mL | Less than 14 pmol/L | | 12–13 yr | | | | Male | Less than 100 pg/mL | Less than 347 pmol/L | | Female | Less than 7 pg/mL | Less than 25 pmol/L | | 14–15 yr | | | | Male | 4–140 pg/mL | 13.88–486 pmol/L | | Female | Less than 10 pg/mL | Less than 34.7 pmol/L | | 16–17 yr | | | | Male | 38–173 pg/mL | 132–600 pmol/L | | Female | Less than 10 pg/mL | Less than 34.7 pmol/L | | Adult | | | | Male | 50–224 pg/mL | 173.5–777.28 pmol/L | | Female | 1–9 pg/mL | 3.47–31.23 pmol/L | | Postmenopausal | 1–6 pg/mL | | | Older adult | | | | Male | 5–75 pg/mL | 17.35–260.25 pmol/L | | Female | 1–8.5 pg/mL | 3.47–29.5 pmol/L |
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Study type: Blood collected in a red-, red/gray-, or green-top [heparin] tube; related body system: Endocrine and Reproductive systems.
Testosterone is the major androgen responsible for sexual differentiation. In males, testosterone is made by the Leydig cells in the testicles and is responsible for spermatogenesis and the development of secondary sex characteristics. In females, the ovary and adrenal gland secrete small amounts of this hormone; however, most of the testosterone in females comes from the metabolism of androstenedione. Testosterone levels have a slight diurnal variation with the highest levels occurring around 0800 and lowest levels around 2000.
Measurements of total testosterone levels are used most often in evaluating suspected hormone imbalances. Free testosterone is the active form of the hormone. It is used in conjunction with total testosterone to evaluate hormone levels in conditions known to alter the effectiveness of testosterone-binding protein, also called sex hormone–binding globulin (SHBG). Alterations in the affinity of SHBG to bind free testosterone are known to occur with obesity, liver disease, and hyperthyroidism. In males, a testicular, adrenal, or pituitary tumor can cause an overabundance of testosterone, triggering precocious puberty. In females, adrenal tumors, hyperplasia, and medications can cause an overabundance of this hormone, resulting in masculinization or hirsutism.
Factors That May Alter the Results of the Study
- Drugs and other substances that may increase testosterone levels include barbiturates, bromocriptine, cimetidine, flutamide, gonadotropin, levonorgestrel, mifepristone, moclobemide, nafarelin (males), nilutamide, oral contraceptives, rifampin, and tamoxifen.
- Drugs and other substances that may decrease testosterone levels include cyclophosphamide, cyproterone, danazol, dexamethasone, diethylstilbestrol, digoxin, D-Trp-6-LHRH, ethyl alcohol, fenoldopam, goserelin, ketoconazole, leuprolide, magnesium sulfate, medroxyprogesterone, methylprednisone, oral contraceptives, pravastatin, prednisone, spironolactone, tetracycline, and thioridazine.
Potential Nursing Problems: Assessment & Nursing Diagnosis
| Problems | Signs and Symptoms |
|---|
| Body image (related to altered male sexual development secondary to lack of testosterone) | Negative verbalization of physical appearance and lack of male attributes, preoccupation with lack of physical body changes, distress and refusal to talk about appearance, negative verbalization about physical appearance | | Sexuality (related to insufficient testosterone level) | Delayed puberty, poor development of muscle mass, minimal body hair, insufficient penile and testicle growth, gynecomastia (breast development), arms and legs grow faster than the body trunk, erectile dysfunction, infertility, osteoporosis |
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Before the Study: Planning and Implementation
Teaching the Patient What to Expect
- Discuss how this test can assist with evaluating hormone levels.
- Explain that a blood sample is needed for the test.
After the Study: Implementation & Evaluation Potential Nursing Actions
Treatment Considerations
Body Image
- Assess the patient’s perception of physical appearance.
- Note the frequency of negative comments about lack of male attributes associated with physical appearance.
- Provide reassurance that physical appearance may change with testosterone therapy.
- Provide a referral to local support groups.
Sexuality
- Explain the importance of testosterone replacement therapy.
- Administer prescribed testosterone replacement medication.
- Discuss concerns regarding intimacy and the potential effect of hormone replacement therapy.
Clinical Judgement
- Consider support groups that could assist in the identification of positive coping strategies to address feelings of inadequacy.
Follow-Up and Desired Outcomes
- Understands that the lack of development of male attributes is associated with inadequate testosterone and that hormonal therapy may support male attribute development.
- Agrees to counseling associated with concerns related to erectile dysfunction and intimacy.