was ist östrogen — what does this mean exactly?

Estrogen is a collective term for a group of steroid hormones primarily known for regulating female reproduction and secondary sexual characteristics. The main forms are estradiol (E2), estrone (E1), and estriol (E3). Estrogen is produced mainly in the ovaries, but also in smaller amounts in the adrenal glands, adipose tissue, and in males, the testes. It influences numerous bodily functions: bone metabolism, cardiovascular health, mood, skin integrity, and the menstrual cycle. An imbalance – either excess or deficiency – can be linked to symptoms like hot flashes, cycle irregularities, weight gain, or increased risk for certain cancers. DNA tests for estrogen-related genes (e.g., CYP19A1, ESR1, COMT) can indicate genetic predispositions, but effect sizes are generally small and not sufficient for clinical diagnosis. The evidence for such tests is mostly mechanistic or observational. Hormone levels should always be evaluated by a physician, especially when symptoms are present. Estrogen is not a 'female-only hormone' – it plays important roles in men as well, such as maintaining bone density and libido.