What is it?

Underweight refers to a person whose BMI is lower than18.5. Being underweight can be caused simply by physical characteristics that run in the family. Other reasons for being underweight include frequent physical activity, food restraint such as in anorexia nervosa, physical illness or chronic illness and mental illness including depression, anxiety, obsessive compulsive disorder and anorexia nervosa. Some of the people who are underweight could experience other symptoms and complications, as mentioned below.

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Signs & symptoms

Some of the people who are underweight could experience osteoporosis, thinning skin hair loss, dry skin, poor dental health, getting sick frequently, longer illnesses, fatigue, dizziness, headaches, fatigue, irregular periods, premature births, slow and impaired growth.


Diagnosis of underweight is done by calculating the BMI. Then, further evaluation for the cause of underweight should be done. Sometimes, a psychiatrist or a psychologist must meet the patient for diagnosis of mental problems.


Treatment for underweight depends on the condition causing it. For weight gaining, a nutritionist can help build a menu that could help the person gain weight and eat better. Other problems, like anorexia nervosa, should be treated with psychotherapy, and sometimes with medications such as SSRI’s.

☝️ This is not a substitute for professional medical advice. Please consult with your physician before making any medical decision.

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