What percentage of weight change in 6 months is considered abnormal?

10 pounds or more.

Explanation:

Unexplained  or abnormal weight loss refers to a noticeable drop in body weight that happens when a person isn't trying to lose weight. It can be a sign of a serious disease, such as cancer or diabetes and to stop it, it is necessary to identify the cause of it. In this case, a 5% of body weight or 10 pounds can be considered abnormal.

try rubbing alcohol

explanation:

i-i-i-i-i-i don't k-k-k-k-know.