What does it mean when your nipples get hard and have stayed hard?

Hormonal...: It is probably hormonal... It can occur when you are sexually excited!

Nipple Erections : Read this article about a patient who experienced unilateral nipple erection==>http://goaskalice.Columbia.Edu/nipple-erections-why. In general, this is not a sign of any pathology; it is mostly potentially embarrassing to you. Unless you experience discharge from the nipples, try the suggestions in the article first. If still a concern, schedule an appointment with your doctor.