I am a 21 year old female. i checked my weight today and i weighted 100.9 pounds. my height is 5'3. am i at my healthiest weight? help me!

BMI 18: Given the information that you provided, your BMI is about 18 which is underweight. While the formula alone is not a perfect measure of health, it suggests that you are not a your healthiest weight. To start, stay hydrated and eat a healthy diet. Your doctor can help you determine what other steps might be good for you to achieve better health.