Currently, two views are commonly used to explain illnesses. One is that people get sick by the presence/infection of some invisible particles (viruses). Second, illness reflects the body’s detoxification process to eliminate toxins. Doctors and health experts often promote and support both views, implied as science-based.
Note that these are opinions or narratives presented as theories to sound factual and scientific. However, these theories are not supported by actual science. Both viruses and toxins (cell debris) are imaginary and fictional objects/substances. No scientific evidence supports the presence or existence of such entities and their relevance.
The only way to make such a claim scientifically valid and acceptable is that the so-called viruses or the toxins must be isolated, purified, and fully (physically and chemically) characterized, and these must be available as such in vials or test tubes. Nothing of this sort happens or is available. Hence, all these claims are scientifically baseless.
Use caution when considering doctors’ (medical and health experts’) science as actual science. There is no medical/health science. It is a made-up science (fake and false) based on personal opinions and narratives.
A better alternative to understanding and addressing illnesses is to try to understand the body’s chemistry, i.e., the working of chemicals (in and outside the body). It is essential to note that the body is built on chemicals (fats, proteins, sugars, minerals, vitamins, water, oxygen, etc), and these are supplied by food and the environment. An imbalance of these can result in issues (called illnesses) and should easily be addressed by appropriate testing and adjusting chemical imbalances. Please consider studying the science of chemicals (chemistry) or seek help from science/chemistry experts.
What is science, and who are scientists? (link)
An M.D. degree is not a science degree! (link)