The majority of people who work in rehabs and are involved in the day-to-day fellowships of Alcoholics Anonymous will probably have a sense of belief that alcoholism is an illness, although it is also often referred to as a disease.
The notion of alcoholism as an illness really first took root in the 1930s during the formation of Alcoholics Anonymous, and it was the growth of Alcoholics Anonymous that helped to cement this idea that alcoholics were ill people, not merely morally weak or hopeless characters.
The early members of AA and the doctors who were helping them at the time gave some sense of what they understood this illness to be by characterising it in certain terms which are available in the book Alcoholics Anonymous.
The book Alcoholics Anonymous and these doctors did not seek to define alcoholism, merely to give it a more real context in the light of their understanding of what it meant.
For many people, it is relatively easy to grasp the idea that alcoholism is an illness, that people who are alcoholics or ill or sick people. Anyone who is close to an alcoholic or who has seen their behaviour at close range can probably understand this, without necessarily understanding what the illnesses is or what it means.
Many organisations, although not AA, refer to alcoholism as a disease. There is some dispute about this idea, but that is beyond the realms of Alcoholics Anonymous. The main problem with identifying alcoholism as a disease, as opposed to an illness, is medical terminology.
Alcoholism
Most people will identify a disease as being something that you catch, with specific symptoms and recovery processes.
The nature of alcoholism is that it is incredibly varied and wide in terms of how it affects the individual.
Many a members whilst accepting that alcoholism is a illness would struggle to define what that illness is. For many of them it is simply a felt sense that the compulsion to drink alcohol or something over which they had no mental control, either at the outset of their drinking or at some point further down the line.
The book Alcoholics Anonymous makes a distinction between an alcoholic and a heavy drinker. It says that the heavy drinker can stop drinking if needs be, albeit with difficulty and even possibly some withdrawals. The alcoholic at some point is unable to stop drinking, nor wishes to.
In many ways it is almost irrelevant whether alcoholism is an illness or not, and certainly thinking about the disease concept or the illness approach is very much an individual choice.
The important thing is that an alcoholic can get sober and stay sober, and if in a rehab can use the therapeutic approaches that the rehab has to help them understand the internal trigger points that can fuel their alcoholism, and that the rehab can help them heal these trigger points and move forward with their life.