A prolactinoma is a small, benign pituitary tumor that over-produces the hormone prolactin. Because prolactin touches many body systems, the signs can be subtle at first and easy to blame on stress or aging.

In women of child-bearing age, periods often lighten or stop altogether. Breast milk may leak even though there is no pregnancy or nursing; some notice a few drops on a bra or during a shower.

Fertility drops. Couples can try for months without success, and libido often fades—interest in sex feels like a switch that will not turn on.

In men, the first tip-off is usually sexual: erections become unreliable, facial hair grows slower, and muscles feel softer despite regular workouts. Milk-like fluid from the nipples is possible but less common.

Both sexes can notice Vision changes. The tumor nudges the optic nerves from below, nipping the outer edges of sight—bumping into doorframes or missing cars in the left or right lane.

Headache is dull and centered behind the eyes, worse when bending forward to tie shoes.

Mood may flatten. Joy feels muffled, and small tasks take big effort, mimicking depression.

Skin turns oilier or drier, and acne may reappear long after the teen years.