Explanation:
You can check if you're underweight by using our BMI healthy weight calculator, which shows your body mass index (BMI). If your BMI is below 18.5, this suggests that your weight may be too low. If you're underweight, or you're concerned that someone you know is, tell a GP or practice nurse.
It has to be ongoing for SIX MONTHS OR LONGER to be chronic. some can be diagnosed within 12 weeks if it continueswith medication use
