It's not necessarily a disease but more like a drug. And just like most other drug, you can get addicted to it. And that would mean you would be spending all your time and effort to gamble which is bad for you.
A disease on the other hand is more like a disorder or a malfunction of a human part.
Yeah, it is like a disease, then, it can be easily cured with medicine. Gambling is far more than a disease; it is a big time emotional and mental disorder in a way. This is the reason why a lot of people end up going through rehabilitation at least to get out of it. Diseases can easily be gotten out from, but not something like addiction where your self-control has been fully hijacked. This is why it is necessary to be in control as much as possible even if you want to end up gambling.
many reasons why someone can be addicted to gambling, one of them is because they like the game and they can do gambling activities every day so it can be concluded that someone who is addicted to gambling is almost similar to a disease that is difficult to cure