由于致热原的作用使体温调定点上移而引起的调节性体温升高，称为发热。发热本身不是疾病，而是一种症状。引起发热的常见原因包括感染、结缔组织病、恶性肿瘤以及药物反应等。治疗发热应主要针对病因治疗。详细询问病史（包括流行病学资料）和认真系统的体格检查对于疾病诊断非常重要。

Normal body temperature ranges 36.5～37.5 ℃(98～100℉).Fever(also known as pyrexia or temperature colloquially)occurs when the body temperature is 37.5℃ or above.Fever may be present in many different conditions,commonly in infections, connective tissue disorders,cancer or drug-reaction of certain drugs are the common clinical reasons of fever.

Treatment is aimed at:①symptomatic relief using an anti-pyretic, e.g., acetaminophane(also known as paracetamol), or non-steroidal anti-inflammatory drugs(NSAIDs)such as ibuprofen; and②treating the underlying cause, e.g., antibiotics for bacterial infectioncaused fever.

Clinical assessment should include a review of the patients’ past medical and drug history, and physical examination.Investigations may include routine blood tests, culture and sensitivity analysis of the blood, urine,sputum, and chest X-ray, where appropriate.Patients with neutropenia may not show the usual symptoms/signs of infection, they should be assessed more closely.

D: Good morning.How may I help you?

P: I have a temperature from time to time, doctor.

D: When did it begin?

P: It started 3 days ago.

D: Did you take your temperature?

P: Yes.Most of the time it was around 38℃.But last night it was as high as 39.2℃.I took some paracetamol and drank lots of water.After that, the temperature came back down.

D: How often do you feel feverish?

P: Not very often.Sometimes I feel feverish in the morning when I woke up, and sometimes in the afternoon.

D: Have you taken any other medication?

P: I have been taking the antibiotic, amoxil and Chinese medicine against viruses, but they do not work.

D: Do you have any other symptoms or problems apart from fever?

P: I have sore throat for a week, and a little bit of dry cough.Each time temperature goes above 38, my head aches but not too severely.

D: How is your appetite?

P: Okay.

D: Any problems with your water works or bowels?

P: No.

D: Do you feel weak or lethargic?

P: Not exactly.But these days I nod off easily.I sleep more and feel tired during the day which is not normal for me.

D: May I examine you, please?

P: Yes, of course doctor.

D: Thank you.Please take off your shirt and socks, and lie down on the bed.There is a blanket here for you to cover yourself.Let me know when you are ready.Close the curtain and wait.After the examination.

D: You have an inflamed throat and swelling of the tonsils, which I suppose is making you feverish.In addition, I find rash(tiny red spots, tiny petechiae)spreading on your legs.And you looked pale, that’s why I asked if you felt tired.

P: Is there something seriously wrong with me, doctor?D: I don’t know yet.We should do a blood test in the first instance to find out more.Please take this blood form to the phlebotomist to have your blood taken.

D: I am sorry that your blood test is abnormal.I am afraid it’s not very good.Both your red blood cell and platelet counts are low.Your white cell count is high with immature blood cells.You may have leukemia,we need to do more tests to be sure whether this is the case or not.I recommend that you be admitted to hospital for us to do the tests and start the right treatment for you, as soon as possible.

D: Hello! Miss.Sit down please.Can I help you?

P: I feel very bad recently.

D: What’s troubling you?

P: I have intermittent fever.My joints ached a lot, and my face turns red especially after been in the sun.

D: For how long have been having this problem?

P: About two weeks.

D: Did you take your temperature? What’s the highest?

P: 39 degrees.

D: Do you have fever every day?

P: Almost every day.Sometimes druing the day and sometimes at night.I took acetaminophen which lowers the temperature.

D: Do you feel hot and cold(shivering)?

P: Sometimes I feel cold before the temperature goes up.

D: Tell me about your joint ache.

P: My knees hurt so much.I went to a Community Health Center yesterday.The doctor did some blood tests and X-ray.He said my X-ray was OK, but there was something wrong with my blood test results.So I come here.

D: Do you feel any other discomfort?

P: I get mouth ulcers.Can you tell me what’s wrong with me?

D: Well, according to your symptoms and the blood test results, there is a strong possibility that you have SLE,short for systemic lupus erythematosus.

P: What is SLE?

D: SLE is an autoimmune disease.This means that the body’s immune system attacks healthy tissues instead of attacking only bad things like bacteria and viruses.This causes inflammation.Common symptoms and signs include lethargy, joint pain or swelling, fever and skin rash.The rash often happens after you have been in the sun.You may also get mouth ulcers/sores(ie broken skin inside the mouth)and hair loss.Some people with lupus also develop problems with the heart, lungs, kidneys, blood cells, or nervous system.

P: Oh no, am I in a serious condition?

D: SLE can respond well to treatment.I recommend trying steroids in the first instance.

P: Thank you.Ok, doctor.

D: Please come back to see me again after you have taken the medicine for one week.

P: Yes, I will.Goodbye!

D: Goodbye.

(P:Patient; D:Doctor)