Your risk of developing a vaginal yeast infection can be increased by a number of medical and lifestyle factors.

Some of the common risk factors for vaginal yeast infection include:

• Use of antibiotics. These medicines upset the normal balance between yeast and bacteria in the vagina. Antibiotics can kill too much "good" bacteria and result in too much yeast growing in the vagina, sometimes causing symptoms of a yeast infection.
• Problems with your immune system that affect the normal balance of yeast and bacteria in the body. Having a condition such as poorly controlled diabetes or HIV (human immunodeficiency virus) can lead to too much yeast growing in the vagina. Taking corticosteroid medicines sometimes also weakens the immune system and increases the risk for yeast infections. Pregnant women are also at higher risk for developing yeast infections because of shifting hormones that can weaken the immune system.
• Wearing tight-fitting, nonabsorbent pants or undergarments that hold in warmth and moisture.
• Using feminine hygiene sprays, talcs, or perfumes in the vaginal area.
• Douching.

Vaginal yeast infections are not sexually transmitted. However, if you have risk factors for a sexually transmitted disease, you may have an increased risk of an imbalance in the organisms of the vagina, which could lead to a vaginal yeast infection.