I've recently noticed that my nipples have this puffy look when they're warm, but they seem perfectly normal and even shrink when it's cold. I'm 23 and this really makes me hesitant to take off my shirt around others. There's no lump under my nipples, so I know it's not gynecomastia. I'm wondering if there's any way to get this sorted out for good. Could you please shed some light on this?