The Estradiol test measures the level of estradiol, a primary form of estrogen in both women and men. This hormone is crucial for various bodily functions, including reproductive health, bone density, and mood regulation. In women, estradiol plays a vital role in the menstrual cycle and fertility. Abnormal estradiol levels can lead to symptoms such as mood swings, weight changes, and reproductive issues. This test is essential for anyone looking to understand their hormonal balance and address any concerns related to estrogen levels.