Causes of Interstitial Cystitis
Researchers are working to understand the causes of IC and to find treatments that work. Even though the exact cause of IC is unknown, you may find that certain events or factors start, or trigger, your symptom flares. Symptom flares can make your IC feel worse. Some people have reported that their symptom flares happen when they

are stressed, or have certain emotions, such as anger or sadness
have sex
have a menstrual cycle
have a urinary tract infection
urinate or hold urine for too long
skip meals or are dehydrated
feel changes in the seasons or the weather
have allergies
go through sudden or bumpy movements
take certain medicines or forget to take their medicines
wear tight pants and undergarments
use laundry detergents with certain chemicals
use certain brands of toilet paper
do certain physical activities
have a Pap smear
take antidepressants , sinus medicines, or pain relievers

Talk with your health care professional about flare management. If you know which factors make your symptoms flare, you may wish to avoid them. However, if factors that affect your health-like having sex, having a Pap smear, or taking certain medicines-make your symptom flares occur, talk with your health care professional right away.