thyroid profile, complete blood count, kidney function test, urine routine and microscopic and stool test should be done.
Unintentional and unexplained weight loss
is definitely not good. There are many causes like worms in stool, depression, anorexia nervosa, AIDS, cancers especially colon cancers, drug abuse, infections and loss of appetite. Loss of appetite can again be due to certain medications, drug abuse, depression, AIDS, acute and chronic infections, cancers and hypothyroidism.