A 6-year-old child who is always umming and clearing his throat may be caused by upper respiratory tract infection or rhinitis. 1. Respiratory tract infection: may be due to bacterial, viral infection caused by inflammation of the throat, can produce pain, or foreign body sensation, which in turn leads to the child constantly clearing his throat. 2. Rhinitis: may lead to post-nasal drip, nasal secretions tend to flow backward, that is, to the throat, resulting in nasal mucus stimulation of the throat with a foreign body sensation, the child will appear always clear throat phenomenon. 6-year-old child always hmmm clear throat, there may also be other reasons such as tics, etc., it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, give targeted treatment or treatment.