Cystitis is the most common disease of the urinary system and has the following five causes: 1. There are specific and non-specific bacterial infections of the bladder. The former refers to bladder tuberculosis. Non-specific cystitis is caused by Escherichia coli, Escherichia coli Paracoccidioides, Proteus mirabilis, Pseudomonas aeruginosa, Streptococcus faecalis and Staphylococcus aureus. 2. Infection by septic bacteria. Causes include stones, foreign bodies, tumors or obstructive lesions, including urinary dysfunction due to neurological disorders. 3, there is a special inflammatory change is gangrenous cystitis, for Clostridium perfringens, Clostridium perfringens and other causes of severe bladder inflammation. 4, Acute cystitis mainly consists of mucosal congestion, edema, bleeding and ulcer formation with pus or necrotic tissue. Chronic cystitis is mainly caused by mucosal hyperplasia or atrophy, granulation tissue formation with fibrous tissue hyperplasia and reduced bladder capacity; or concurrent obstruction caused by muscle hypertrophy, increased bladder capacity or even diverticulum formation and other changes. 5, bad habits. For example, when sex does not pay attention to hygiene, or too often, for the bladder system are harmful. In addition to going to public bathrooms as well as pools without paying attention to hygiene, resulting in infection, can also induce cystitis. Even if you don’t have sex and don’t go to public places during the day, you are also at risk of contracting cystitis. For example, if you like to eat very irritating food, drink and smoke a lot, or sit and not move, or hold your urine, all of these can cause cystitis.