What is the primary cause of cystitis, which can lead to painful urination?

The primary cause of cystitis is the inflammation of the bladder, which is typically a result of bacterial infections, although non-infectious factors can contribute as well. When the bladder becomes inflamed, it can lead to symptoms such as painful urination, frequent urges to urinate, and discomfort in the pelvic area. This condition is commonly seen in urinary tract infections (UTIs), where pathogens irritate the bladder lining.

While urinary retention, kidney stones, and urethral obstruction can create problems within the urinary system, they are not the direct cause of cystitis. Instead, these conditions might lead to symptoms similar to those of cystitis or can contribute to an increased risk of developing a urinary tract infection, but they do not define the inflammation of the bladder itself. Therefore, the emphasis on "inflammation of the bladder" captures the true nature of cystitis and its direct impact on urination.