ANDROPAUSE / LATE-ONSET MALE HYPOGONADISM
Etymology, Pathophysiology, Modern Endocrinological Diagnosis, Hormonal Therapy, Cardiovascular Controversies, and Referral Criteria to Urology and Endocrinology
Advanced Medical-Scientific Review Updated 2026
By DrRamonReyesMD ⚕️
ETYMOLOGY AND MEDICAL TERMINOLOGY
The term:
“ANDROPAUSE”
derives from the Greek:
“ANDROS” (ἀνήρ / ANDRÓS) = man, male.
“PAUSIS” (παῦσις) = cessation, interruption.
Literally:
“male cessation.”
However:
from a modern endocrinological perspective, the term is imperfect.
Why?
Because:
men do NOT experience an abrupt and universal cessation of gonadal function comparable to female menopause.
Menopause involves:
relatively abrupt ovarian follicular depletion,
dramatic estrogen decline,
universal physiological infertility.
In contrast, men:
may maintain androgen production into advanced age,
often preserve partial fertility,
and exhibit an extremely heterogeneous hormonal decline.
Therefore, modern scientific societies prefer more precise terminology:
male hypogonadism,
testosterone deficiency syndrome,
LOH (Late-Onset Hypogonadism),
or testosterone deficiency syndrome.
Current guidelines from the:
European Association of Urology (EAU),
American Urological Association (AUA),
and the Endocrine Society
agree on a critical point:
“andropause” is NOT diagnosed solely based on fatigue or aging.
Diagnosis requires:
compatible symptoms + biochemically confirmed low testosterone.
()
PHYSIOLOGY OF THE HYPOTHALAMIC–PITUITARY–GONADAL AXIS
Testosterone is primarily synthesized by:
testicular Leydig cells.
Endocrine regulation:
Hypothalamus → GnRH (Gonadotropin-Releasing Hormone) → Anterior Pituitary → LH / FSH → Testis.
PHYSIOLOGICAL FUNCTIONS OF TESTOSTERONE
Testosterone is involved in:
libido,
nocturnal erections,
erectile function,
spermatogenesis,
bone mineral density,
erythropoiesis,
muscle mass,
fat distribution,
glucose metabolism,
insulin sensitivity,
cognition,
motivation,
energy,
emotional regulation.
AGING AND TESTOSTERONE
After the fourth decade:
total testosterone declines approximately 0.8–1.5% annually.
Free testosterone declines even faster due to increasing:
SHBG (Sex Hormone-Binding Globulin).
However:
aging does NOT automatically equal endocrine disease.
Many elderly men:
maintain functional testosterone levels,
partial fertility,
and preserved sexual function.
PATHOPHYSIOLOGY OF MALE HYPOGONADISM
PRIMARY HYPOGONADISM (HYPERGONADOTROPIC)
Testicular gonadal failure.
Biochemical characteristics:
low testosterone,
elevated LH,
elevated FSH.
Etiologies include:
,
viral orchitis,
chemotherapy,
radiotherapy,
testicular trauma,
torsion,
gonadal aging,
.
SECONDARY HYPOGONADISM (HYPOGONADOTROPIC)
Hypothalamic or pituitary dysfunction.
Characteristics:
low testosterone,
low or inappropriately normal LH/FSH.
Common etiologies:
visceral obesity,
obstructive sleep apnea,
,
opioids,
corticosteroids,
hyperprolactinemia,
pituitary adenomas,
systemic diseases,
chronic stress,
severe energy deficit.
METABOLIC SYNDROME AS A GONADAL SUPPRESSOR
Visceral obesity promotes:
peripheral aromatization of testosterone → estradiol,
chronic inflammation,
insulin resistance,
hypothalamic dysfunction,
LH suppression.
Therefore:
many modern “LOW T” cases are metabolic rather than purely gonadal.
THE MODERN PROBLEM: THE “LOW T INDUSTRY”
There is currently:
aggressive commercial medicalization of androgen deficiency.
Particularly driven by:
digital marketing,
anti-aging clinics,
fitness influencers,
male cosmetic medicine,
TRT used for performance enhancement.
This has generated:
overdiagnosis,
unnecessary TRT,
endocrine trivialization,
psychological dependence on therapy.
Several recent publications criticize the creation of a commercially marketed pseudo-pathology of male aging.
CLINICAL MANIFESTATIONS
SEXUAL
decreased libido,
loss of morning erections,
erectile dysfunction,
infertility,
reduced sexual frequency.
PHYSICAL
loss of muscle mass,
increased visceral adiposity,
osteoporosis,
osteopenia,
fatigue,
reduced strength,
anemia.
NEUROPSYCHIATRIC
apathy,
depression,
irritability,
impaired concentration,
brain fog,
sleep disturbances,
reduced motivation.
THE DIAGNOSTIC CHALLENGE
These symptoms are:
highly nonspecific.
They may result from:
depression,
burnout,
stress,
sleep apnea,
diabetes,
obesity,
alcohol use,
hypothyroidism,
systemic illness,
physiological aging.
MODERN DIAGNOSIS IN 2026
FUNDAMENTAL RULE
A single testosterone value is NOT sufficient.
The recommends:
morning testosterone measurement,
between 07:00–11:00,
fasting state,
confirmation in TWO separate samples.
IMPORTANT THRESHOLDS
EAU
Total testosterone:
<12 nmol/L
as a symptom-associated reference threshold.
AUA
<300 ng/dL
as a reasonable diagnostic threshold.
()
RECOMMENDED LABORATORY WORKUP
Before TRT:
total testosterone,
calculated free testosterone,
SHBG,
LH,
FSH,
prolactin,
TSH,
PSA,
complete blood count,
glucose/HbA1c,
lipid profile,
liver function,
ferritin if hemochromatosis is suspected.
WHEN TO SUSPECT PITUITARY PATHOLOGY
Particularly if:
extremely low testosterone,
low LH,
headache,
galactorrhea,
visual disturbances,
hyperprolactinemia.
In such cases:
pituitary MRI is mandatory.
TESTOSTERONE REPLACEMENT THERAPY (TRT)
Indicated ONLY in:
confirmed hypogonadism + clinically significant symptoms.
NOT:
“to feel younger,”
or for gym performance enhancement.
PHARMACOLOGICAL FORMS
1. TRANSDERMAL GEL
Examples:
Advantages:
more physiological levels,
easy dose adjustment.
Limitations:
cutaneous transfer,
adherence issues,
variable absorption.
2. INTRAMUSCULAR TESTOSTERONE UNDECANOATE
Typical European regimen:
initial dose,
second dose approximately 6 weeks later,
then every 10–14 weeks.
3. ENANTHATE / CYPIONATE
More commonly used in the United States.
Problems:
hormonal peaks and troughs,
mood and metabolic fluctuations.
POTENTIAL BENEFITS OF TRT
TRT may improve:
libido,
sexual function,
energy,
body composition,
bone density,
anemia,
muscle mass.
DOI: 10.1210/jc.2018-00229
IMPORTANT RISKS
1. POLYCYTHEMIA
One of the most relevant complications.
Monitor:
hematocrit.
2. INFERTILITY
TRT suppresses the gonadal axis.
It decreases:
FSH,
LH,
spermatogenesis.
Particularly important in younger men.
3. OBSTRUCTIVE SLEEP APNEA
May worsen significantly.
4. FLUID RETENTION
Use caution in:
heart failure,
hypertension,
elderly patients.
5. PROSTATE
Current evidence does NOT demonstrate a clear increase in prostate cancer risk with properly monitored TRT.
However:
PSA,
digital rectal examination,
and urological surveillance
remain essential.
DOI: 10.1016/j.eururo.2025.03.032
MONITORING
Monitor:
testosterone,
PSA,
hematocrit,
metabolic profile,
blood pressure,
symptoms,
weight.
Follow-up:
initially at 3 months,
then every 6–12 months.
ERECTILE DYSFUNCTION AND TESTOSTERONE
Important:
NOT all erectile dysfunction is androgenic.
Most cases are:
vascular,
metabolic,
psychological,
or pharmacological.
ASSOCIATED MEDICATIONS
PDE5 Inhibitors
FERTILITY-PRESERVING THERAPIES
In patients wishing to preserve fertility, clinicians often prefer:
HCG,
clomiphene,
gonadotropins
instead of direct TRT.
WHEN TO REFER TO UROLOGY
Referral is recommended in cases of:
confirmed low testosterone,
significant sexual symptoms,
infertility,
complex erectile dysfunction,
abnormal PSA,
testicular mass,
significant gynecomastia,
TRT failure,
suspected malignancy,
elevated hematocrit,
young patients.
WHEN TO REFER TO ENDOCRINOLOGY
Particularly in cases of:
hyperprolactinemia,
suspected pituitary disease,
secondary hypogonadism,
complex obesity/metabolic dysfunction,
multiple endocrine abnormalities.
CONCLUSIONS
The condition commonly referred to as “andropause” represents a multidimensional process involving:
aging,
metabolism,
sleep,
endocrinology,
vascular health,
mental health,
and gonadal function.
The major modern mistake is:
labeling any male fatigue syndrome as “LOW T.”
TRT can dramatically improve quality of life in appropriately selected patients.
However, it may also lead to:
infertility,
polycythemia,
therapeutic dependence,
overtreatment,
unnecessary medicalization.
Evidence-based modern medicine requires:
accurate biochemical diagnosis,
rigorous etiological evaluation,
precise patient selection,
strict monitoring,
and appropriate specialist referral.
SCIENTIFIC REFERENCES
European Association of Urology
American Urological Association
Endocrine Society
KEY DOI REFERENCES
Bhasin S et al. Testosterone Therapy in Men With Hypogonadism.
DOI: 10.1210/jc.2018-00229
Mulhall JP et al. Evaluation and Management of Testosterone Deficiency.
DOI: 10.1016/j.juro.2018.03.115
Salonia A et al. EAU 2025 Update on Male Hypogonadism.
DOI: 10.1016/j.eururo.2025.03.032
