Most NCDs increase in prevalence with age – a consequence of the cumulative exposure to risk factors (including unhealthy behaviors such as tobacco use and biological risk factors such as high blood pressure) over a lifetime. All else being equal, larger and older populations mean more people with NCDs.
世界上有很多地区同时发生着人口的增加和老化。大部分NCD的出现伴随着年龄的老化——这是一生中累积风险因素的结果（包括吸烟等不健康行为以及高血压等生物性风险因素）。在其他条件相同的情况下，人口的增加和老化意味着更多的人患上NCD。