Final answer:
Hormone replacement therapy, which often includes estrogen, can make fibrocystic breast disease worse due to its effect on hormonal balance and potential to cause fluid retention and breast pain.
Step-by-step explanation:
Fibrocystic breast disease, a common condition characterized by benign lumps in the breast, can be influenced by hormonal changes in the body. Options like pregnancy and breastfeeding typically do not make fibrocystic breast disease worse. In fact, they can sometimes alleviate symptoms. However, Hormone replacement therapy (HRT), which generally involves the intake of estrogen, could potentially exacerbate the condition as it influences the hormonal balance of the body. Estrogen can lead to fluid retention and may cause breast pain or enlargement of the cysts associated with fibrocystic breast changes.