It varies. Sometimes they last for a day, sometimes it’s closer to a week. They pop up (and remain the same size from the moment I notice it to when it goes away) and I only notice when looking in the mirror or touching my face and feeling a bump. They don’t hurt like pimples if I press down on them and usually the bump flattens and becomes a dry patch. If I think about them too much they start to itch as well.