Cold temperatures (e.g. cold feet) enable bacteria to settle in the gallbladder. It mostly affects women, because their urinary tract is shorter, thus leading the bacteria straight to their destination.
Treatment for cystitis
The juice contains, besides Vitamin C (an immune-modulator), large quantities of antibiotic flavonoids. The watercress mustard oil has an anti-bacterial effect similar to penicillin. Liquids drunk in large quantities aid the direct elimination of pathogens.
Here you can find another very useful natural remedy for cystitis.
Be healthy, Be natural!