Final answer:
Hyperestrogenism refers to an excessive amount of estrogen in the blood, which is distinct from conditions like PCOS that involve excessive androgens.
Step-by-step explanation:
The term that refers to having an excessive amount of estrogen in the blood is Hyperestrogenism. This condition can be associated with a range of symptoms and health risks, including the growth of uterine fibroids and endometrial hyperplasia, which could increase the risk of endometrial cancer. Conditions like Polycystic ovary syndrome (PCOS) are related to the endocrine system but are characterized by excessive androgens rather than estrogen.