High prolactin is one of the most common hormone imbalances we see in clinic, and long-term it can really impact your fertility and ability to conceive. Prolactin normally goes high when you’re pregnant or breastfeeding because it helps with breast milk production. But if you’re neither of those things, it usually goes elevated because of high stress and high cortisol. On rare occasions, a pituitary tumour can also increase levels, so if prolactin is consistently high, we want to rule that out.