What are the common causes and diseases that lead to fever in children?

There are various common causes and diseases that lead to fever in children, mainly including: 1. Infectious factors: such as viral infections (e.g., influenza virus, rhinovirus, etc.) and bacterial infections (e.g., Gram-positive or Gram-negative bacteria). These pathogens can cause respiratory, gastrointestinal, or urinary tract infections, leading to fever in children. 2. Non-infectious factors: including connective tissue diseases (e.g., rheumatic fever, juvenile idiopathic arthritis, etc.), tissue damage or necrosis (e.g., leukemia, malignant tumors, etc.), hypersensitivity reactions (e.g., drug fever, serum sickness, etc.), and dysfunction of the body's temperature regulation center (e.g., heat intolerance syndrome, etc.). Fever in children can be caused by either infectious or non-infectious factors. When parents notice their child has a fever, they should seek timely medical attention. A qualified physician should make a targeted diagnosis and provide appropriate treatment based on the child's specific symptoms and clinical signs.