You got your labs back. The reference ranges are wide. Some numbers are bolded as "out of range," some aren't. You have no idea what you're actually looking at. Here's the field guide.
Total Testosterone
Total Testosterone includes free and protein-bound testosterone. A single result of 320 ng/dL does not establish testosterone deficiency. Diagnosis requires relevant symptoms and consistently low measurements interpreted using the assay's reference range and clinical context.
A clinician generally confirms a low result with repeat morning fasting testing. Timing, illness, medicines, and measurement methods can affect interpretation; a trend alone is not a diagnosis.
Free Testosterone
Free Testosterone is the fraction not bound to circulating proteins. Testosterone loosely bound to albumin can also be biologically available; protein-bound testosterone is not uniformly unavailable to tissues.
Free Testosterone can help when Total Testosterone is near the lower limit or SHBG is altered. Use the laboratory's assay-specific reference range. The guideline recommends equilibrium dialysis or a validated calculation using Total Testosterone, SHBG, and albumin rather than a direct analog assay.
SHBG (Sex Hormone Binding Globulin)
SHBG binds testosterone and affects the relationship between Total and Free Testosterone. A high or low SHBG result is not, by itself, a diagnosis of an estrogen problem.
SHBG can vary with conditions affecting the liver, thyroid, or metabolism and with some medicines. A clinician uses this context when interpreting testosterone results.
Estradiol (E2)
Yes, men have estrogen, and they need some of it. Estradiol matters for bone density, mood, libido, and joint health. Too low is as bad as too high.
Estradiol results should be interpreted with symptoms, treatment, and the assay used. This article does not establish a universal optimal level or a testosterone-to-estradiol treatment ratio. Do not change treatment to pursue a number without clinical assessment.
LH and FSH
LH and FSH are pituitary hormones involved in testosterone and sperm production. With low testosterone, elevated levels can suggest a testicular cause; low or inappropriately normal levels can suggest a hypothalamic or pituitary cause. Further evaluation determines the cause.
Treatment options depend on the cause, symptoms, medical history, and fertility goals. These results do not by themselves select a medicine.
Tests a clinician may consider
The appropriate tests depend on the history, examination, and initial results. Not everyone needs every test below.
- Total Testosterone: morning fasting testing, with confirmation of a low result
- Free Testosterone, SHBG, and albumin: when needed to clarify testosterone status
- LH and FSH: to help distinguish testicular from hypothalamic or pituitary causes
- Prolactin: may identify excess prolactin in selected cases; a normal result does not rule out all pituitary tumors
- Other tests: chosen for symptoms, possible causes, and treatment monitoring; selected cases need pituitary assessment or imaging
The bottom line
Ask your clinician what each result means, whether repeat testing is needed, and which additional tests would change care. More tests are not automatically better; interpretation and follow-up matter.
Sources
Endocrine Society: July 2026 statement on testosterone therapy; MedlinePlus: testosterone levels test; Endocrine Society: hypogonadism in men; Testosterone therapy guideline: testing and interpretation; MedlinePlus: SHBG blood test; Endocrine Society: testosterone therapy guideline.