yes, your hair can fall out, your skin can turn all types of colors including blue depending on what your natural tone is; you can get a grayish cast, a yellowish cast to your skin, w/e. you can have sagging skin, hollow eyes, irregular heart beats that lead to heart problems, and a myriad of other problems that aren't beautiful.
to prevent it you eat a balanced diet of at least 1200-1500 cals depending on your bmr. make everything you eat nutritionally packed with vitamins and minerals. take supplements like a multivitamin, iron, biotin, vitamin e, calcium, vitamin d, magnesium, potassium, etc, to supplement what you don't get daily with your food. and you can stretch and do exercises in moderation and you should be fine. xx