The Estradiol (E2) test is used to measure the level of estrogen, which is one of the primary sex hormones in both women and men. Estrogen is primarily produced in the ovaries in women, and it plays a role in regulating the menstrual cycle, egg development, and pregnancy health. This test is typically performed to assess ovarian function, diagnose menstrual disorders, and monitor hormonal treatments, such as hormone replacement therapy. In men, it may be used to evaluate estrogen levels in certain conditions, such as infertility or abnormal symptoms. Estrogen levels are influenced by several factors, including age, menstrual cycle, and medications. Elevated or low levels can indicate potential health issues, such as polycystic ovary syndrome (PCOS) or pituitary gland disorders. The estradiol test is an important tool for understanding hormonal balance and providing appropriate treatment when needed.