Breast size is determined by a mix of genetic and environmental factors. Hormonal changes during pregnancy and when the breasts start to produce milk can also cause breasts to get bigger. Sometimes large breasts can be the result of gigantomastia, a rare condition that causes excessive growth of the female breasts.
What do bigger breasts mean?
Hormonal Changes: Women develop their breasts during puberty as estrogen increases. Pregnancy and milk production can also cause the breasts to enlarge due to hormonal changes. Drug Use: Certain drugs can lead to enlarged breast tissue in both men and women.