I have had a mole on my side for as long as I can remember. It has always been roughly 2mm, brown, very slightly raised with distinct borders, and has never changed size. I hadn t checked on it for a long time and just 2 days ago I noticed that it was now black and more raised than it had ever been. Since then it has changed literally over night. Yesterday a 1mm border grew that was a redish brown, and today the mole is no longer black, but instead has changed back to a lighter brown color. In total, it is roughly 5mm in diameter now with one side raised and the border being flat. I tried to make an appointment over the weekend but every dermatologist in the city was closed on weekends. How common is over night changes in moles? I understand these are generally warning signs for a potentially dangerous mole but I was not able to find anything online about over night changes, so could this change any possible diagnosis?