Testosterone is the most important male sex hormone, and it influences muscle, bone, drive, mood and sexual function. From around age 40 it falls slowly and naturally, by roughly one to two percent per year, which is why German endocrinologists say there is no sudden "male menopause".
A real Testosteronmangel is more than a low number, because the diagnosis needs two things at the same time:
- Clear symptoms are present such as persistent tiredness, a low sex drive, loss of muscle or low mood.
- Blood samples taken in the morning show repeatedly low values, because a single measurement is never enough for the diagnosis.
The morning matters because testosterone is highest early in the day and falls towards the evening, so an afternoon value can look falsely low.
Several everyday factors reduce testosterone, and sometimes the value recovers once they change:
- Extra body weight reduces the amount of testosterone your body makes.
- Not sleeping enough lowers testosterone as well.
- Heavy alcohol use has the same effect on the value.
- Some illnesses and some medicines lower testosterone too.
If you recognise those signs in yourself, the right next step is a doctor, usually a urologist or an endocrinologist, who can measure properly and rule out other causes. Testosterone products without a confirmed deficiency and a prescription are a bad idea, because buying them on your own is risky.
In this glossary, the Nüchternblutabnahme explains morning blood draws, and the Referenzbereich explains how to read the range next to your value.
This glossary entry is general information, not medical advice, and it is not intended to diagnose, treat or rule out any condition. Discuss your own results with a clinician who knows your history.
