Generally, it can be divided into two types: typical and mild, and there is also recurrent typhus.1. Typical symptoms incubation period is 5 to 21 days, with an average of 10 to 12 days. A few patients have 2 to 3 days of prodromal symptoms, such as fatigue, headache, dizziness, chills, low fever. Most of them have an acute onset with chills, severe and persistent headache, peripheral muscle pain, and congestion of the conjunctiva and face. (1) Fever? Body temperature peaks on the 2nd to 4th day (above 39～40℃), with an auditory type in the 1st week and a flaccid tendency from the 2nd week onwards. The course of fever is usually 14 to 18 days, and the body temperature rapidly recedes to normal within 2 to 4 days. In the cases reported in recent years, the fever pattern is mostly flaccid or irregular, which may be related to the application of antibiotics. (2) Rash? It is an important sign, seen in more than 80% of the cases, appearing on the 4th to 6th day of the course of the disease, initially seen on the chest, back, axilla, sides of the upper arm, etc., and then rapidly developing to the whole body within a day. There is usually no rash on the face and fewer rashes on the lower extremities. The rash is round or oval, about 2-4mm in diameter, initially bright red macules, which fade when pressed, and then turn into dark red or petechiae. The rash subsides in 5-7 days, and the petechiae-like rash may last for 1-2 weeks, leaving brownish-yellow spots or flakes. (3) Neurologic symptoms? Obvious and very early appearance, manifested as panic, excitement, severe headache, the onset may be accompanied by mental retardation, delirium, occasional meningeal irritation signs, muscle and tongue tremor, coma, urinary and fecal incontinence, dysphagia, hearing loss and so on. (4) Cardiovascular symptoms? Heart rate increase is generally proportional to the increase in body temperature, and gallop rhythm and arrhythmia can occur when there is toxic myocarditis. Shock or hypotension is a combined consequence of water loss, microcirculatory disorders, cardiovascular and adrenal hypofunction. (5) Other symptoms? There are still cough, chest pain, shortness of breath, nausea, vomiting, nausea, constipation, abdominal distension, etc. Occasionally, there are jaundice, cyanosis, and renal hypoplasia. Mildly enlarged spleen, hepatomegaly in some cases.2. Mild mild cases are more common, probably related to the immunity level of the population, which are characterized by: (1) shorter duration of fever (8-9 days), lower fever (about 39℃); (2) less severe toxaemia symptoms, but there is still obvious peripheral pain; (3) congestive maculopapular rash, which is seen in the chest and abdomen, and there is a certain percentage of people with no rash; (4) mild neurological symptoms, short duration, mainly showing headache and pain. (4) neurological symptoms are mild, short duration, mainly manifested as headache, excitement, etc.; (5) hepatosplenomegaly is uncommon.3. Recurrent typhus, also known as Brill-Zinsser's disease, is mostly seen in Eastern Europe and Eastern Europeans migrating to the United States, and the disease is rarely reported in China. The main clinical manifestations can be summarized as follows: (1) a mild form of passage, toxaemia symptoms and central nervous system symptoms are mild; (2) flaccid fever, fever duration of 7 to 11 days; (3) no rash, or only a sparse maculopapular rash; (4) dissemination, non-seasonal, the incidence of the older age groups is significantly higher.