SN instructed thats cystitis is inflammation of the bladder, usually caused by a bladder infection. It's a common type of urinary tract infection ( UTI ), particularly in women, and is usually more of a nuisance than a cause for serious concern. Mild cases will often get better by themselves within a few days. However, some people experience episodes of cystitis frequently and may need regular or long - term treatment. There's also a chance that cystitis could lead to a more serious kidney infection in some cases, so it's important to seek medical advice if your symptoms don't improve.