關於「疾病」這個話題，總有很多個問題。例如，疾病一共有多少種？疾病是如何進行分類的？究竟是什麼導致了疾病的發生？我們又該如何預防疾病呢？在接下來的幾周，我們將對「疾病」這一重要概念進行學習，希望在學習結束後，大家都能對這些問題有所答案。
Diseases can be classified differently. For instance, an epidemic disease is one that strikes many persons in a community. When it strikes the same region year after year it is an endemic disease. An acute disease has a quick onset and runs a short course. An acute heart attack, for example, often hits without warning and can be quickly fatal. A chronic disease has a slow onset and runs a sometimes years-long course. The gradual onset and long course of rheumatic fever makes it a chronic ailment. Between the acute and chronic, another type is called subacute.
疾病可以劃分為不同的種類。例如，流行病是指在某一社區內感染很多人的疾病；當流行病年復一年地侵襲同一社區，就形成地方病。急性病發作快，但病程短。例如，急性心臟病發作常常沒有前兆，而且會很快致命。然而，慢性病發作慢，但病程有時會長達幾年。風溼熱因為發病慢且病程長而成為一種慢性病。此外，介於急性與慢性之間，還有另一種類型，即亞急性。
Disability and illnesses can also be provoked by psychological and social factors. These ailments include drug addiction, obesity, malnutrition, and pollution-caused health problems.
心理因素和社會因素也會引發殘廢和疾病，其中包括藥物成癮、肥胖、營養不良和由汙染造成的健康問題。
Furthermore, a thousand or more inheritable birth defects result from alternations in gene patterns. Since tiny genes are responsible for producing the many chemicals needed by the body, missing or improperly operating genes can seriously impair health. Genetic disorders that affect body chemistry are called inborn errors of metabolism. Some forms of mental retardation are hereditary.
此外，基因型的變化可能造成上千種甚至更多的遺傳性出生缺陷。由於小小的基因負責生產許多機體所需的化學物質，基因的遺失或不適當的工作狀態都會嚴重損害健康。因基因失調而影響體內化學反應的疾病被稱為先天性代謝缺陷。智力缺陷的一些疾病形式就是遺傳所造成的。
epidemic disease 流行病
endemic disease 地方病
acute disease 急性病
chronic disease 慢性病
subacute 亞急性
malnutrition 營養不良
gene patterns 基因型
mental retardation 智力缺陷
hereditary 遺傳的
今天的分享就到這啦。下周我們會繼續學習關於疾病的分類。歡迎大家持續關注~