【正文】 ine of defense is in the blood and lymph. Certain white blood cells flock to infected areas and try to localize the infection by forming pusfilled abscesses. Unless the abscess breaks and allows the pus to drain, the infection is likely to spread. When this happens, the infection is first blocked by local lymph glands. For example, an infection in the hand travels up the arm, producing red streaks and swollen, tender lymph glands in the armpit. Unless the infection is brought under control, it will result in blood poisoning. Phagocytes are located at various sites to minimize infection. One type in the spleen and liver keeps the blood clean. Others in such highrisk areas as the walls of the bronchi and the intestines remove certain bacteria and shattered cells.位于身體不同部位的吞噬細(xì)胞能最大程度地減少感染。如果膿塊不破裂，里面的膿不排出，感染很可能會(huì)擴(kuò)大。即使能在這種溫度下生存繁殖的病菌，在體溫升高發(fā)燒時(shí)也會(huì)被殺滅。另外，呼吸道內(nèi)覆有一層叫纖毛的細(xì)小絨毛，能象麥田里的小麥一樣舞動(dòng)，輕輕地將異物掃出呼吸道。在一些較輕的病情中，可能只會(huì)發(fā)生癤子和丘疹。蒼蠅能將病菌從人類的排泄物或其他腐爛的物質(zhì)帶到食物和飲料中；蚊子、虱子或其他媒介動(dòng)物的叮咬也會(huì)將病菌傳入人體。一般來講，身體防御系統(tǒng)能夠抵抗這些入侵者。由于小小的基因負(fù)責(zé)產(chǎn)生許多身體所需的化學(xué)物質(zhì)，它們的缺失或者運(yùn)行不良都會(huì)嚴(yán)重?fù)p害健康。一些疾病也可能由飲食不足、身體抵抗力下降或神經(jīng)系統(tǒng)運(yùn)行不良造成。有時(shí)，一種致病菌侵入人體后，該人卻沒有顯示患病的癥狀。Diseases can be classified differently. For instance, an epidemic disease is one that strikes many persons in a munity. 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 yearslong 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. 疾病也可以依其病原體來劃分，例如，傳染病指可以在人與人之間傳播的疾病，如可通過咳嗽或打噴嚏造成的飛沫進(jìn)行傳播。例如，急性心臟病發(fā)作常常沒有前兆，而且會(huì)很快致命。Hundreds of different diseases exist. Each has its own particular set of symptoms and signs, clues that enable a physician to diagnose the problem. A symptom is something a patient can detect, such as fever, bleeding, or pain. A sign is something a doctor can detect, such as a swollen blood vessel or an enlarged internal body organ. 疾病可按不同的標(biāo)準(zhǔn)來分類。例如，人類常常被微小的細(xì)菌感染，但是細(xì)菌又轉(zhuǎn)而可能被更加微小的病毒感染。然而不把病理學(xué)包括進(jìn)去，這種概述是不完整的，因?yàn)椴±韺W(xué)是研究疾病引起的結(jié)構(gòu)和功能變化的學(xué)科。實(shí)際上，現(xiàn)代對疾病的研究方法強(qiáng)調(diào)病理學(xué)與生理學(xué)的密切關(guān)系，并強(qiáng)調(diào)在治療任何人體疾病時(shí)了解病理學(xué)與生理學(xué)基礎(chǔ)的必要性。Then what is a disease? It may be defined as a condition that impairs the proper function of the body or of one of its parts. Every living thing, both plants and animals, can succumb to disease. People, for example, are often infected by tiny bacteria, but bacteria, in turn, can be infected by even more minute viruses. 世界上有數(shù)百種疾病,每一種都有其特定的癥狀和體征，這些都是醫(yī)生診斷疾病的線索。例如，流行病是感染某一地區(qū)許多人的疾病。慢性病發(fā)病緩慢，但病程有時(shí)會(huì)長達(dá)數(shù)年。極小的有機(jī)體，如細(xì)菌和真菌,可導(dǎo)致傳染病。于是無癥狀的病原攜帶者甚至在自己也不知情的情況下就把疾病傳染給了他人。Noninfectious diseases are caused by malfunctions of the body. These include organ or tissue degeneration, erratic cell growth, and faulty blood formation and flow. Also included are disturbances of the stomach and intestine, the endocrine system, and the urinary and reproductive systems. Some diseases can be caused by diet deficiencies, lapses in the body’s defense system, or a poorly operating nervous system. 心理因素和社會(huì)因素也會(huì)引發(fā)殘疾和疾病。影響人體化學(xué)反應(yīng)的基因失調(diào)被稱為先天性代謝失調(diào),某些智力發(fā)育遲緩有遺傳性。Humans live in a world where many other living things pete for food and places to breed. The pathogenic organisms, or pathogens, often broadly called germs that cause many diseases, are able to invade the human body and use its cells and fluids for their own needs. Ordinarily, the body’s defense system can ward off these invaders. 病原體能通過多種方式進(jìn)入人體。Insects can spread disease by acting as vectors, or carriers. Flies can carry germs from human waste or other tainted materials to food and beverages. Germs may also enter the body through the bite of a mosquito, louse, or other insect vector. 身體如何抵抗疾病作為第一條防線，健康的身體有許多物理屏障來抵御感染。在較重的情況下，身體的大面積區(qū)域則可能會(huì)被感染。另外，呼吸道內(nèi)的異物還常通過擤鼻涕、咳嗽、打噴嚏和清嗓子而被排出。Many potential invaders cannot stand body temperature ( oF or 37 oC). Even those that thrive at that temperature may be destroyed when the body assumes higher fever temperatures. 外耳道里的蠟質(zhì)和淚管里的眼淚能減緩一些細(xì)菌的生長速度，而胃酸也能毀掉某種吞食進(jìn)去的病菌。發(fā)生這種情況時(shí)，感染首先被該區(qū)域的淋巴腺阻擋。肝和脾內(nèi)的吞噬細(xì)胞能保持血液清潔。In most clinical encounters, the patient presents basic questions to the doctor: What’s wrong with me? What is causing my illness? These questions set the stage for making a diagnosis, . determining the cause of an illness. And a diagnosis is acplished with history, physical examination and laboratory testing.疾病的診斷過程由采集病人的病史開始，醫(yī)生向病人詢問當(dāng)前和過去所患的疾病、家族病史、生活習(xí)慣等等。患者的其他醫(yī)生姓名、地址、電話號(hào)碼以與患者的關(guān)系現(xiàn)病史 每種主要癥狀，包括什么癥狀、發(fā)生部位、發(fā)生時(shí)間、輕重程度、時(shí)間 經(jīng)過、癥狀好轉(zhuǎn)或加重的影響因素、既往診治情況及可能縮小診斷范圍 相關(guān)的問題既往史既往疾病及住院情況、免疫情況、用藥情況、過敏史、飲酒、吸煙及有無藥物成癮等社會(huì)及職業(yè)史描述患者日常生活中典型的一天以及目前疾病對其生活的影響；患者可獲得的社會(huì)支持（來自家庭、朋友或同事）及職業(yè)史家族史家族中的遺傳病史，家族成員的壽命及死亡原因各系統(tǒng)的評估主要器官系統(tǒng)的系統(tǒng)性評估：皮膚、造血系統(tǒng)（包括淋巴結(jié)），頭、眼、耳、鼻、口、喉、頸、乳房、呼吸系統(tǒng)、心血管系統(tǒng)、胃腸道系統(tǒng)、泌尿生殖系統(tǒng)、肌肉骨骼系統(tǒng)、神經(jīng)系統(tǒng)、內(nèi)分泌系統(tǒng)和精神系統(tǒng)Description of patientAge, gender, race, occupation and parity (for woman)Chief plaintFour or five words, preferably quoting the patient, stating the purpose of the visit and the duration of the plaint. Occasionally the patient states a request instead of a plaint such as I need a flu shot.Other physicians involved in the patient’s careName, address, telephone number, and relationship to the patientHistory of the present illnessFor each major symptom, what, where, when, how much, chronological course, what makes the symptom better or worse, past medical care, questions to narrow diagnostic possibilitiesPast medical historyPrevious illnesses and hospitalizations, immunizations, medications the patient takes, allergies, and alcohol, tobacco and drug habitsSocial and occupational historyDescription of a typical day in the patient’s life and how the present illness affects it, social supports (family, friends, and colleagues) available to the patient, and occupational historyFamily historyHistory of genetically related diseases in the patient’s family and longevity and cause of death of family mem