The clinical manifestations of Q fever are varied and depend mainly on the number and strain of pathogens entering the body, the immunity of the individual, and the underlying disease. The incubation period ranges from 9 to 30 days, with an average of 17 to 20 days. The following symptoms can be used for preliminary diagnosis. 1. Self-limiting fever The most common clinical manifestation form of Q fever. There is only fever, no pneumonia, and the course of the disease is self-limiting, usually 2 to 14 days. 2, Q fever pneumonia can be clinically manifested as atypical pneumonia, rapidly progressive pneumonia and pneumonia without pulmonary symptoms. Almost all patients have fever with chills or chills, and the body temperature rises 39℃～40℃ within 2～4 days in flaccid form; most patients have obvious headache; in addition to fever and headache, there are also muscle pain (especially lumbar muscle and gastrocnemius muscle), facial and conjunctival congestion, diarrhea, fatigue, sweating, and exhaustion, and occasionally pain behind the eyes and arthralgia, without There is no skin rash. Respiratory symptoms are not prominent. Patients develop a dry cough and chest pain with a small amount of mucous sputum or blood in the sputum after 3 to 4 days of the disease. On physical examination, a few wet rales can be heard at the base of the lungs, and signs of pulmonary solidity are present with rapidly progressive pneumonia. Most patients have no respiratory symptoms. The duration of this type of Q fever is usually 10 to 14 days. 3, chronic Q fever The number of cases is increasing and deserves attention. The fever often lasts for more than several months, and the clinical manifestations are diverse. In addition to being easily complicated by endocarditis, pneumonia, hepatitis, etc., it can also be accompanied by pulmonary infarction, myocardial infarction, interstitial nephritis, arthritis and osteomyelitis, etc., either alone or in combination. 4. other Patients with Q fever may have combined aseptic meningitis or (and) encephalitis, often with severe headache, but the brain tissue lesions are not significant. meningitis or (and) encephalitis caused by Q fever is rare, and there may be elevated white blood cell counts in the cerebrospinal fluid, ranging from tens to hundreds or even thousands, with mononuclear cells predominating. Protein levels are usually elevated and glucose levels are normal. Other neurological complications include muscle weakness, recurrent meningitis, blurred vision, and behavioral abnormalities. spinal osteomyelitis, bone marrow necrosis, and hemolytic anemia may occasionally occur in patients with Q fever.