Dependence on alcohol or other addictive substances is, of course, a serious problem affecting the health of the person suffering in the broadest sense of the word.
Moreover, it is a problem that affects one of the essential elements of human beings: freedom.
The person who develops alcohol dependence is losing its ability to decide if you drink or not drink in certain situations, gradually loses self-control of their own behavior, ultimately: is losing its freedom.
We therefore consider it a disease, because it affects the personal balance between the patient and his environment, and because proper treatment to recover from it is required.
However it is not a common disease that can be "cured" by taking certain medications, by surgery or some other common medical procedure.