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.
Milia are small (1 or 2 mm), round white bumps that usually happen on the head and neck. These are common in infants and in adults. In adults, they are often a sign of chronic sun damage. Milia can spontaneously rupture, drain, and resolve on their own, but this make up to 2 years.