There is no such thing as three signs of urinary tract infection. Clinical symptoms of urinary tract infection include urinary tract irritation signs (urinary frequency, urgency, urinary pain, etc.), symptoms of infection toxicity (fever, chills, headache, etc.), and lumbar discomfort. 1. Urinary tract irritation signs: mainly manifested as urinary frequency, urinary urgency, urinary pain, urinary discomfort, lower abdominal pain and other symptoms. It is mainly due to the growth and reproduction of pathogenic microorganisms in the urinary tract, leading to the localization of the above symptoms. 2. Symptoms of toxicity of infection: systemic symptoms include fever, chills, headache, body aches, nausea, vomiting and other symptoms. The most common causative organism of urinary tract infection is gram-negative bacillus, and bacterial invasion of the human body will easily lead to the above symptoms. 3. Lower back discomfort: pain in the lower back on the affected side or both sides, and obvious pressure or percussion pain in the angle of the rib spine. The above symptoms are caused by the infection involving the kidneys. If the patient has a urinary tract infection, it is recommended to go to the regular hospital in time, under the guidance of the doctor to standardize the treatment.