Clinical Indications for Suspecting Low Testosterone (Hypogonadism)

Suspect low testosterone when patients present with characteristic symptoms (reduced libido, erectile dysfunction, fatigue, reduced energy) OR when they have specific high-risk medical conditions, even without symptoms. 1

Symptom-Based Indications

Clinicians should suspect hypogonadism when patients report any combination of the following symptoms:

Sexual and Reproductive Symptoms

Reduced sex drive or libido 1
Changes in erectile function 1
Male infertility 1

Physical and Metabolic Symptoms

Reduced energy and endurance 1
Diminished work and/or physical performance 1
Persistent fatigue 1
Gynecomastia (breast tissue enlargement) 1

Cognitive and Mood Symptoms

Depression 1
Reduced motivation 1
Poor concentration 1
Impaired memory 1
Irritability 1

Specialized Symptoms

Visual field changes, specifically bitemporal hemianopsia (suggests pituitary pathology) 1
Anosmia (loss of smell, suggests Kallmann syndrome) 1

Physical Examination Findings

A targeted physical examination should assess for signs that strongly suggest testosterone deficiency:

Reduced body hair in androgen-dependent areas (face, chest, pubic region) 1
Increased body mass index or waist circumference (central obesity) 1
Gynecomastia 1
Small or soft testes (normal adult testicular volume is 15-25 mL) 1
Presence of varicocele 1
Abnormal prostate size or morphology 1

High-Risk Medical Conditions (Screen Even Without Symptoms)

The American Urological Association recommends measuring testosterone in patients with the following conditions, regardless of whether hypogonadal symptoms are present: 1

Hematologic and Metabolic

Unexplained anemia 1
Diabetes mellitus 1

Bone Health

Bone density loss or osteoporosis 1

Oncologic and Treatment-Related

History of exposure to chemotherapy 1
History of testicular radiation (direct or scatter) 1

Infectious Disease

HIV/AIDS 1

Medication-Related

Chronic narcotic use 1
Chronic corticosteroid use 1

Endocrine Disorders

Pituitary dysfunction 1
Male infertility 1

Liver Disease

Chronic liver disease with menstrual irregularity or evidence of hypogonadism 1

Critical Diagnostic Algorithm

When hypogonadism is suspected based on symptoms or risk factors, follow this stepwise approach:

Obtain two separate morning (8-10 AM) total testosterone measurements using the same laboratory and methodology 1, 2
- Diagnosis requires levels consistently <300 ng/dL 1, 2
- Morning timing is essential due to diurnal variation 1, 3
Measure luteinizing hormone (LH) in all patients with low testosterone to distinguish primary (testicular) from secondary (hypothalamic-pituitary) hypogonadism 1, 2
Measure serum prolactin if LH is low or low-normal to screen for hyperprolactinemia and possible pituitary tumors 1, 2
Consider free testosterone measurement in specific situations: 2, 4, 3
- When total testosterone is near the lower limit of normal (230-350 ng/dL) 3
- In obese patients where SHBG may be altered 4, 3
- When SHBG abnormalities are suspected 2
- Use equilibrium dialysis method when available 2, 3

Common Pitfalls to Avoid

Do not rely on screening questionnaires alone - they have variable sensitivity and specificity and should not replace clinical evaluation and laboratory testing 1, 4
Do not measure testosterone at random times of day - afternoon or evening measurements may be misleadingly low due to normal diurnal variation 1, 3
Do not diagnose hypogonadism based on a single testosterone measurement - at least two separate morning measurements are required 1, 2
Do not overlook free testosterone in obese patients - total testosterone may be misleadingly low when SHBG is altered, but free testosterone may be normal 4, 3
In patients with chronic liver disease and elevated SHBG, express testosterone as a ratio of total testosterone/SHBG (free testosterone index), where <0.3 indicates hypogonadism 1, 3

What are the indications for suspecting low testosterone (hypogonadism)?

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