What primary hypogonadism is
Primary hypogonadism is low testosterone that starts in the testes: the signal from the brain is strong, but the testes cannot produce enough hormone in response. MedlinePlus describes it as the form of hypogonadism in which the gonads themselves malfunction, as opposed to central or secondary hypogonadism, where the pituitary or hypothalamus is the problem.
Because the pituitary senses low testosterone, it raises LH and FSH to push harder. That is the hallmark: low testosterone with high LH and FSH. The same testes also make sperm, so fertility is often affected too.
Signs build slowly in adults and can include:
- lower sex drive and fewer morning erections
- smaller or softer testes
- breast tenderness or enlargement
- less body and facial hair, and slower shaving
- loss of muscle, more body fat and lower bone density
- difficulty conceiving
When it begins before puberty, the picture looks different: delayed or incomplete puberty, long arms and legs, and a high voice.
What causes it
The causes fall into two groups: conditions you are born with and damage that happens later.
| Cause | Notes |
|---|---|
| Klinefelter syndrome (47,XXY) | The most common genetic cause; MedlinePlus Genetics estimates about 1 in 650 male newborns and up to 65 percent never diagnosed |
| Undescended testes in childhood | Higher risk of later testicular failure even after repair |
| Mumps orchitis | Testicular inflammation after puberty can damage hormone-making cells |
| Injury or torsion | Trauma or a twisted testicle can cut off blood supply |
| Chemotherapy or radiation | Common after testicular cancer and some blood cancers |
| Iron overload, liver or kidney disease | MedlinePlus lists these among primary causes |
| Autoimmune disease | Rare; the immune system targets testicular tissue |
Klinefelter syndrome has its own page on Klinefelter syndrome and testosterone, and cancer survivors can read about low testosterone after testicular cancer. Shrinking testes from other causes are covered on our testicular atrophy page.
How it is confirmed
Confirmation takes three things: low testosterone on two separate early-morning tests, high LH and FSH, and symptoms that fit.
- Repeat morning testosterone. The AUA guideline requires two early-morning total testosterone measurements before diagnosing low testosterone, with under 300 ng/dL as a reasonable cutoff.
- LH and FSH. The Endocrine Society recommends measuring both to separate testicular from pituitary causes. In primary hypogonadism, both run above the reference range. MedlinePlus lists mumps, injury to the testicles, testes that never developed normally, chromosomal disorders such as Klinefelter syndrome, and damage from chemotherapy or radiation among the causes of high LH in men. Our FSH test for men page covers the second marker.
- Follow-up tests by clue. A karyotype when testes are small and FSH is very high, a semen analysis when fertility matters, iron studies when iron overload is possible, and an exam of the testes in every case.
When LH is high but testosterone is still normal
Some men have a high LH with a testosterone that is still in range. The testes are keeping up, but only because the pituitary is pushing harder than usual. This pattern, often called compensated hypogonadism, is common after losing a testicle or after chemotherapy. It is usually watched with repeat testing rather than treated, since testosterone may hold steady for years or drift down slowly.
Recent anabolic steroid use, a current illness or a high SHBG can all muddy these readings, so your provider times the draws and reads them in context.
Reference ranges for LH and FSH differ between labs, so results are read against the range printed on your report. If LH and FSH come back low or normal instead, the problem sits higher up; see secondary hypogonadism in men.
Why HCG cannot restart production here
HCG works by imitating LH, and in primary hypogonadism LH is already high. The AUA describes HCG as an LH analog that is usually used when the body is not making enough LH. In secondary hypogonadism, that extra signal can wake up healthy testes. In primary hypogonadism, the testes are already being flooded with LH and still cannot respond, so adding an LH look-alike has little to work with.
This is why the type of hypogonadism matters so much before treatment. Men with a pituitary cause have options that preserve their own production; men with a testicular cause usually do not. Our comparison of HCG vs TRT lays out when each makes sense.
Treatment paths and fertility
For most men with confirmed primary hypogonadism and fitting symptoms, testosterone therapy replaces what the testes no longer make. Options include injections, oral testosterone undecanoate (Kyzatrex) and pellets. The choice depends on your schedule, comfort with needles, and how your levels and blood count respond.
Fertility comes first in the planning if you might want children. Testosterone therapy lowers sperm production further, and the AUA advises that men who are trying to conceive should not receive it. A semen analysis, a fertility specialist’s opinion and, in some cases, sperm banking or surgical sperm retrieval should happen before therapy starts. Our page for men trying to conceive goes through those steps.
Monitoring follows any start: testosterone levels, hematocrit, PSA in men over 40, and how symptoms respond.
When to get urgent care
Some testicular symptoms are emergencies, not appointments. Go to the ER right away for sudden, severe pain or swelling in a testicle, which can be torsion and needs treatment within hours to save the testicle. A new lump or hard area in a testicle should be checked promptly by a clinician. Call 911 for chest pain or signs of a stroke.
How Ultimate Male confirms and treats it
We confirm the type of hypogonadism before treatment is discussed, because it changes the options. A free 10-minute call sets up a morning draw on site at San Gabriel or Downey, with results in 24 to 48 hours. If your first testosterone is low, your provider adds LH, FSH and a repeat morning test.
In a one-on-one consultation, a PA-C or MD explains what the pattern shows and talks through fertility plans before anything else. When primary hypogonadism is confirmed, the conversation covers testosterone therapy choices and the follow-up labs each requires, and we coordinate with a fertility specialist when children are part of your plans.
