The natural progression of disease over time is a consequence of inherited susceptibility (genetic inheritance) and exposure to environmental factors, including lifestyle. As individuals age, depending on their genetic inheritance along with what they do and what they are exposed to, they may develop a chronic disease which progresses over time. it is becoming more widely understood that chronic disease is often the result of multiple factors rather than one single factor.
Different diseases (i.e., cardiovascular disease, metabolic disease, cancers) have different rates of development. In any case, for a long portion of its development, a disease is not clinically apparent although in many cases it could be detected with appropriate attention and diagnostics. Once signs and symptoms develop, it is generally late in the disease development process and the degree of reversibility is reduced and the cost of treatment is increased compared to interventions at an earlier time.
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