The onset of brucellosis is more frequent in spring and summer, with a high incidence in pastoral areas, and symptoms appear 5 days to several months after bacterial infection, usually 2 weeks. Symptoms include: 1. Fever. Fever is the most common symptom in the acute stage, wave fever or flaccid fever, accompanied by excessive sweating, fever in the chronic stage is not obvious. 2, joint muscle pain. Patients in the chronic phase mostly have wandering large joint pain, and in the acute phase often have severe pain in multiple joints, which can be pinprick-like or stubborn dull pain. The pain in the chronic phase is limited to 1-2 joints, with persistent dull pain or soreness, and long-term recurrent attacks can lead to stiffening or atrophy of tendons and forced deformity of the joints. 3, reproductive system symptoms. Male patients develop testicular inflammation and epididymitis, often unilateral. Female patients develop menstrual irregularities, amenorrhea, premature birth, miscarriage, stillbirth, etc. 4. Neurological symptoms. Due to nerve trunk and nerve root injury, resulting in neuralgia, mostly seen in the acute stage, with lumbosacral nerve, intercostal nerve and sciatic nerve predominating, which can cause back pain and leg pain.5. Lymph nodes and liver and spleen enlargement, usually occurring in the acute stage, mainly seen in the neck and axilla.6. Patients with brucellosis without complications usually recover after 2-3 weeks, complications are rarer, but can infect the heart, brain and meninges, causing nerve , inflammation of the testes, gallbladder, liver and bone.