You should know! #3
Know how to calculate Body Mass Index (BMI).
- BMI can tell whether a patient is overweight or obese; it measures body fat.
- Overweight and obesity are linked with several health issues. Health issues like hypertension, dyslipidemia, diabetes, coronary heart disease, stroke, gallbladder disease, and osteoarthritis represent a few examples.
- Overweight and obesity are linked to morbidity.
- Overweight and obesity are also linked to an increase in all-cause mortality.
- BMI is used in adult men and women and NOT in children.
- BMI measures body fat in relations to height and weight.
- Be careful to interpret the BMI measurement in the context of the patient; for example, with a muscular person, BMI may overestimate body fat while in a small frail elderly person the BMI underestimate body fat(loss of muscle mass).
- In some cases the waist measurement is used along with BMI to predict disease risk; fat around the waist in not good.
- For women, high risk is defined as waist size > 35 inches.
- For men, high risk is defined as waist size > 40 inches.
- Be vigilant for underweight patients as these people may have issues when treating certain diseases; an example would be a frail malnourished patient hospitalized with a weaken immune system trying to fight an infection.
BMI’s are classified in the following chart.
BMI (kg/m2) | Classification |
< 18.5 | Underweight |
18.5-24.9 | Normal weight |
25-29.9 | Overweight |
≥30 | Obese |
≥40 | Extremely Obese |
There are two ways to calculate BMI. Make sure to use the proper units in each method. kg/m2 is the unit for BMI.
Method #1

Method #2

Tag:BMI, you should know