Pharyngeal isthmus mucosal congestion is painless and itchy. Consider conditions such as pharyngeal isthmus mucosal infection, pharyngitis, or tonsillitis, which are milder in nature without associated symptoms. 1. Pharyngitis: due to the infection of the pharyngeal mucosa caused by hemolytic streptococcus, pneumococcus or adenovirus, thus causing congestion of the pharyngeal mucosa early in the course of the disease, but without other obvious symptoms. 2. Acute pharyngitis: during the attack, it is easy to cause nasopharyngeal mucosal congestion, and pain and itching may not appear when the condition is mild. 3 acute tonsillitis: such as tonsil congestion, swelling as the main manifestation of acute kata tonsillitis or lymphoid follicle congestion, swelling, suppuration of acute follicular tonsillitis usually also cause pharyngeal isthmus mucosal congestion. In short, pharyngeal isthmus mucosal congestion is mainly due to the presence of infection caused by pharyngeal inflammation, painless, itchy, may be a milder condition, such as persistent congestion, you can go to the hospital otorhinolaryngology department for consultation, in order to clarify the diagnosis and treatment.