Why is this test important?
This profile serves to clarify symptoms such as fatigue, loss of libido, erectile dysfunction, reduced muscle strength, or unfulfilled desire to have children. It enables diagnosis of hypogonadism (testosterone deficiency) and supports therapy decisions as well as monitoring of treatments.
Included Parameters
- Testosterone (total): Most important male sex hormone, responsible for libido, muscle strength, and energy. Low values indicate testosterone deficiency.
- Free testosterone: Calculated proportion of unbound testosterone that is biologically active. A low value can explain symptoms even with normal total testosterone.
- Free androgen index (FAI): Ratio of testosterone to SHBG, which provides a better assessment of free testosterone.
- SHBG: Transport protein for sex hormones. High values lower the free testosterone proportion, low values increase it.
- DHEAS: Androgen precursor from the adrenal gland. An elevated or lowered value can provide clues about adrenal function or stress.
- Estradiol: Estrogen that in men is produced mainly through conversion of testosterone. Deviations can affect libido, mood, and bone metabolism.
- LH: Hormone from the pituitary gland that stimulates testosterone production in the testes. A low value with testosterone deficiency indicates a problem with the pituitary gland, a high value indicates primary testicular weakness.
- FSH: Control hormone for sperm production. Changes indicate reduced fertility.
- Prolactin: Hormone that when elevated can negatively affect libido and testosterone production. Elevated values can be caused by medications or stress.
Practical Notes on Blood Collection
Blood collection should be performed in the morning between 7 and 10 a.m., as testosterone values fluctuate during the day. Fasting collection after a rest period is recommended. Medications, stress, and acute illnesses can affect values and should be considered in the assessment.
