Your skin is a super-smart organ, and it will inform you when it doesn’t like a certain formula or skin care habit—with breakouts, flushing, scaling, the works. Sometimes these signs are quick and easy to spot (full-blown irritation is pretty hard to miss), but others can fly a bit more under the radar with time. Is your uptick in dryness an innocent byproduct of the weather, or is your skin begging you to forgo a harsh formula?