Body Mass Index (BMI). Body Mass Index (BMI) is measure of body fat based on height and weight that applies to both adult men and women. BMI does not differentiate between body fat and muscle mass. Therefore, body builders and people who have a lot of muscle bulk will have a high BMI but are not overweight or obese.
The bump: or hematoma as we call it, can last for 1-2 weeks. Sometimes it gets slightly worse before it gets better. If the child is acting normally, and not vomiting uncontrollably, she should be fine. If she starts doing those things, call your pediatrician.
Depending on his condition, your baby may wear the helmet for a month or two to as long as six months. Most doctors will instruct you to leave the helmet on for 23 hours each day, removing it only for bathtime. Although this may seem like a lot, the problem will be corrected much faster if you follow instructions.