What Symptoms Indicate The Presence Of Yeast Infection?

After I do a Pilates class 2 days in a row(wearing work out pants), I have a feeling like I am going to get a yeast or bladder infection with that uncomfortable feeling, but no pain and no other issues, so I have found that if I continually take AZO a homeopathic tablet it goes away, but what is causing this and what could I do to stop this. It generally takes a day or two to be back to normal