Thanks for writing to us.
Being lean and thin can be due to many causes and finding out the main cause will help in gaining the weight. Genetics is the main factor responsible. If your parents or siblings are also underweight
then may be it is in your genes. The causes that need to be ruled out are -
2. Addison's disease- A hormonal
problem- Some simple blood tests will rule this out.
3. Chronic illness-A long standing viral illness also causes lack of a healthy look.
4. GERD- I hope you do not have any pain abdomen, loose stools, burning sensation in upper abdomen, etc.
5. Viral gastroenteritis
6. Stress and anxiety.
8. Intestinal worms.
9. Thyroid disorders.
All these causes need to be ruled out with the help of your physician after a thorough examination and some blood tests.
I hope this information has been both informative and helpful for you.
Dr. Rakhi Tayal