The Follicular Stimulating Hormone (FSH) test is used to measure the level of FSH in the blood, which is considered one of the key hormones in the endocrine system. FSH plays an important role in regulating reproductive functions in both men and women. In women, FSH helps stimulate the growth of follicles in the ovaries, leading to egg production. FSH levels are an important indicator of menstrual health and fertility. In men, FSH aids in stimulating sperm production in the testes. This test is usually performed as part of fertility evaluation, to monitor hormonal changes during menopause, or to diagnose conditions like polycystic ovary syndrome or endocrine disorders. A blood sample is drawn from a vein and analyzed in a laboratory, and the results show FSH levels in units such as milli-international units per milliliter (mIU/mL). It is always recommended to consult a doctor to understand the results accurately and their relation to overall health.