发热

title: 测量.
content: 体温一般用体温计测量。高于下列温度之一可认为是发热:腋下温度等于或高于37.2°C(99°F);口腔内温度等于或高于37.7 °C(100°F);肛门、耳温度等于或高于38°C(100.4°F)。  近年来也有通过红外线传感方式测量耳鼓膜温度的耳温枪测温。因测量快速,于2003年SARS流行期间,这类测量在机场等公共场所被用来大规模检测可能携带疾病的旅客。
title: 机理.
content: 导致发热的物质称为“热原”(英语:pyrogen)。主要分两类。外源性是侵入人体的细菌、病毒等产生的毒素直接刺激身体的温度调节中枢(位于大脑内的下视丘),引起体温升高。可见于败血症。  内源性是人体为了抵抗感染,巨噬细胞、白细胞等与入侵生物作用,产生的复合体或代谢产物—目前认为是白介素-1(英语:interleukin-1)—成为热原,刺激发热。
title: 分类 (以口测法为准).
content: 一般建议由医生诊断和治疗的情况有:  中高度以上的发热可能暂时影响大脑功能,造成谵妄(俗称的“胡言乱语”)。持续高热或发生超高热的情况则需要进行急救。在这些温度下人体内的酶会失去活性,从而导致重要代谢过程受阻而死亡。  发热的规律可能预示着特别的疾病,例如伤寒病人常见体温逐渐升高,然后持续呈台阶状; 疟疾患者发热一般呈48或72小时的周期状,而肺结核的特征是每天午后发热。
title: 治疗.
content: 不严重的暂时发热不一定需要治疗。原因如下:  发热会增加心跳和新陈代谢,所以心脏病患者和年老体弱的人应特别考虑及时解除发热症状。  常用的口服解热药物包括阿司匹林、对乙酰氨基酚、布洛芬等。  发热时体液丢失增多,应及时补充,包括多饮水,或者输液。民间“捂汗”(加盖衣被)的退热方法一般不被医学界推荐,因为操作不当可能反而阻止热量散发,对儿童和高热患者尤其危险。

Summary: 发烧(英语:fever),又称作发热(英语:pyrexia)或发烧反应(英语:febrile response),其定义为:体温在调节时超过了平常体温。现在医界并没有一致认可的正常体温上限,文献从37.3到38.3°C都有。下视丘的体温调节中心将原本的体温设定(set point)调高,即为发烧,并让人感到寒冷。这使得身体为了生产更多热而出现肌肉收缩,且开始试图保存热量。当体温调定点回到正常值时(即为退烧时),患者就会开始感到燥热,出现脸红,也可能开始流汗。发烧导致的热性痉挛(较强烈的肌肉收缩)较为少见,然而这在年轻孩童患者之中较为常见。发烧通常不会高到。 发烧是指身体制造过多热能或身体的体温调节失调,导致身体的温度高过温度设定值或温度设定值本身过高。发烧可能是由许多疾病造成,从小病到重症都有可能,这包含了病毒、细菌、寄生、普通感冒、流行感冒、泌尿道感染、脑膜炎、疟疾、阑尾炎等。 非感染性的发烧成因包含了血管炎、深静脉血栓、药物的副作用、癌症等。另外,发烧不等同高热这个类似疾病,不同之处在于,高热(中暑为高热的一种)起因于身体累积的热能过多或是身体的散热功能不足,导致体温超越正常体温设定点。 治疗发烧本身,一般来说是非必要的。然而治疗衍生的疼痛与发炎,有利于患者于生病期间的休养,因为患者会觉得舒服些。布洛芬或对乙酰氨基酚这类药物可能可帮助上述治疗,也可以同时降低体温。在额头放冷的毛巾或是洗个热水澡,不但无效且可能让人更不舒服。三岁以下的幼童或是患有像是免疫缺陷这类严重疾病的患者或出现多重并发症状的人必须立刻送医。高热无论如何也必须立刻送医。 发烧是常见的医学征象之一。体温上升可强化免疫细胞,增加杀死细菌和病毒的能力,发烧也可抑制细菌和病毒在体内繁殖。发烧约占看病孩童中的求诊原因的30%;生重病的成人会有75%的几率出现发烧这个医学征兆。尽管发烧是身体本身的一个强而有力的防卫机制,但是治疗发烧本身并不会让身体的抵抗力降低使得潜在病因的病情恶化。有些家长与医疗从业人士,常会把发烧本身看得太严重,这样的现象被称为发烧恐慌症(英语:fever phobia)。

Fever: Fever, also referred to as pyrexia, is defined as having a temperature above the normal range due to an increase in the body's temperature set point. There is not a single agreed-upon upper limit for normal temperature with sources using values between in humans. The increase in set point triggers increased muscle contractions and causes a feeling of cold. This results in greater heat production and efforts to conserve heat. When the set point temperature returns to normal, a person feels hot, becomes flushed, and may begin to sweat. Rarely a fever may trigger a febrile seizure, with this being more common in young children. Fevers do not typically go higher than. A fever can be caused by many medical conditions ranging from non-serious to life-threatening. This includes viral, bacterial, and parasitic infections—such as influenza, the common cold, meningitis, urinary tract infections, appendicitis, COVID-19, and malaria. Non-infectious causes include vasculitis, deep vein thrombosis, connective tissue disease, side effects of medication, and cancer. It differs from hyperthermia, in that hyperthermia is an increase in body temperature over the temperature set point, due to either too much heat production or not enough heat loss. Treatment to reduce fever is generally not required. Treatment of associated pain and inflammation, however, may be useful and help a person rest. Medications such as ibuprofen or paracetamol (acetaminophen) may help with this as well as lower temperature. Measures such as putting a cool damp cloth on the forehead and having a slightly warm bath are not useful and may simply make a person more uncomfortable. Children younger than three months require medical attention, as might people with serious medical problems such as a compromised immune system or people with other symptoms. Hyperthermia does require treatment. Fever is one of the most common medical signs. It is part of about 30% of healthcare visits by children and occurs in up to 75% of adults who are seriously sick. While fever evolved as a defense mechanism, treating fever does not appear to worsen outcomes. Fever is often viewed with greater concern by parents and healthcare professionals than is usually deserved, a phenomenon known as fever phobia.