One of the most important things that can make a vaginal yeast infection worse is douching! Yes, you read right, douching is a big mistake if you have a yeast infection, or basically at all times.
Many of the medications used to douche with, does not only kill the Candida Albicans fungus (the one giving you the yeast infection) but also all the other fungi and bacteria that have to keep the yeast under control. So, now you can see, this creates the ideal conditions for a yeast overgrowth, and a yeast overgrowth is what causes a yeast infection.
Another factor that can make a yeast infection worse is using anti-bacterial soap. Basically it makes the fungus infection worse for the same reasons as explained above. To be correct, you should only use white, unscented soap to wash with. I have found that a white shower cream that is ph balanced is your best option.
These are only two of the factors that can make a yeast infection worse, go to: Natural Cure Yeast Infection for more on yeast infections. Do take time to browse through the site as there is a lot of good information on it.