Sizable factions within the research and advocacy communities are very interested in having aging officially classified as a disease, meaning its inclusion in the International Classification of Diseases maintained by the World Health Organization, as that is the basis for the definition of disease used by national regulatory bodies. The view is that this would open the door to greater large-scale institutional funding, more relevant clinical trials for therapies targeting the mechanisms of aging, and that this greater level of funding and activity will percolate back down the chain of research and development to accelerate progress. I think this a reasonable argument to make, though I would advocate for greater effort to be placed on finding a way to bypass the system rather than change it directly - the threat of competition tends to be more effective than petitions as a way to force change.
Lobbyists have made more progress towards classifying aging as a disease. The World Health Organization (WHO) has implemented the extension code "Ageing-related" (XT9T) in the latest version of the International Classification of Diseases (ICD). The previous version, the ICD-10, was released in 1983 and is now replaced by the new version, the ICD-11, which is expected to serve the medical community for many years, much as its predecessor has.
In the new ICD code, 'ageing-related' means "caused by pathological processes which persistently lead to the loss of organism's adaptation and progress in older ages". This is an important step forward for our field because ICD codes are a prerequisite for the registration of new drugs and therapies. It also marks the recognition that aging is a pathological process and represents a solid step forward in overcoming regulatory barriers to developing therapies that directly target the aging processes themselves.
WHO reports that by 2050, around 2 billion people (22% of the world's population) will be age 60 or over. This is commonly referred to as the "Silver Tsunami", and it is a real concern because society will become increasingly unable to cope with the rising numbers of elderly and potentially sick people, as aging is the greatest risk factor for multiple age-related diseases. The solution to this problem is to develop therapies that address the aging processes to keep older people healthy, active, and contributing to society rather than being burdens on healthcare systems, and that is without even considering the personal benefit of keeping people alive and healthy.
While the inclusion of the new code in the ICD-11 cannot be regarded as the WHO officially accepting aging as a disease, it does show that the WHO recognizes that aging is the primary risk factor for age-related diseases. There is also considerable debate as to if aging is a disease or not; we propose that it is a co-morbid syndrome. A syndrome is a set of medical signs and symptoms that are correlated with each other and, often, with a particular disease or disorder. This really does describe aging perfectly: it is a group of symptoms that consistently occur together and is a condition characterized by a set of associated symptoms. Ultimately, aging is an umbrella term describing a range of pathological changes; it may struggle to be accepted as a disease, but it already qualifies as a syndrome.