If a new mole does pop up, it has to do with melanocytes, which are the pigment-producing cells that duplicate, and if they do it enough, they'll eventually result in what we know as a mole. Medical News Today says that new moles can appear due to having fair skin, genetics, a weakened immune system, or being exposed to ultraviolet radiation (in other words, the sun). According to Healthline, being pregnant can also cause new moles to appear. Moles may change throughout your life, but a brand new mole should probably be evaluated (via MedicineNet).
If you're someone who is frequently in the sun, the statistics of you having more (or developing new) moles increases. If you have a large number of moles (more than 50), your melanoma risk is much higher. Wearing sunscreen daily and covering your moles is an incredibly important habit to get into (via Skin Cancer Foundation).
