Final answer:
The top causes of death have shifted over the past 100 years from infectious diseases to noninfectious diseases due to improvements in public health, behavioral changes, and medical advances, despite current lifestyle challenges.
Step-by-step explanation:
The overall factors contributing to the top causes of death today versus 100 years ago have shifted significantly due to advances in public health measures, behavioral changes, and medical innovations. A century ago, infectious diseases were the predominant causes of death, with poor sanitation and limited medical knowledge being major challenges. Over time, the introduction of clean water systems, waste disposal, education on hygiene practices, and the development of vaccines and antibiotics drastically reduced mortality from infections.
In the current era, however, there is a trend towards higher rates of noninfectious diseases such as heart disease, stroke, diabetes, and cancer. This shift reflects changes in lifestyle due to technology and social environments that foster sedentary behavior and unhealthy eating patterns. Efforts to reduce smoking and increase awareness about sexually transmitted diseases have also improved overall health.