Chronic cystitis is a disease that occurs after a non-specific bacterial infection such as E. coli and is characterized by recurrent and persistent symptoms of urinary frequency, urgency, and painful urination, partly as a result of incomplete cure of acute cystitis. If necessary, cystoscopy and pathological examination are required to clarify. The main symptoms of chronic cystitis are frequent, urgent, and painful urination, with symptoms that persist, recurring, and for more than three months. The symptoms are relatively mild compared to acute cystitis, and there are usually no symptoms of hematuria. If acute cystitis is not treated thoroughly, it will gradually turn into chronic cystitis. There are also some more specific chronic cystitis caused by non-bacterial infections, such as glandular cystitis and interstitial cystitis. This type of cystitis requires cystoscopy to obtain a biopsy before it can be clarified. The treatment of chronic cystitis is also different from that of chronic cystitis caused by bacterial infection. In summary, chronic cystitis is a disease that is characterized by frequent, urgent, and painful urination, with recurring episodes that do not heal, and has many causes and types that require multiple tests for clarification and targeted treatment.