A common type of urinary tract infection (UTI), particularly common in vagina-owners, that causes symptoms such as pain, burning or stinging when you pee, needing to pee more often than usual, dark or strong-smelling urine, lower abdominal pain and feeling generally unwell. Basically, it sucks.
Mild cases will often get better by themselves within a few days, but some people experience recurrent episodes of cystitis and may need regular or long-term treatment. Occasionally cystitis could lead to a more serious kidney infection and so it's really important to seek medical advice if your symptoms don’t settle.