What kind of condition is a bladder infection?

Bacteria or virus: Bladder infections are due to bacteria or much less commonly viruses multiplying in the bladder. They may involved the bladder lining and wall in which case there are usually symptoms of needing to urinate frquently and having low pelvic pain and burning upon urination. Sometimes blood in urine. Bacterial bladder infections are best treated with antibiotics. Most are not serious.