Causes of Vaginal Yeast Infections

Conditions that may make yeast infections more likely include:

• Pregnancy and other causes of hormone changes.

• Use of oral contraceptives (birth control pills).

• Diabetes that isn't well controlled. High blood sugar can help yeast to multiply.

• A weakened immune system.

• Use of steroid drugs.

• Use of antibiotics. Antibiotic drugs kill bacteria in the body including the vagina, allowing yeast to multiply and cause an infection.

Yeast infections seem to be only rarely passed from one person to another through sexual contact. A male partner of a woman with a yeast infection usually will have no symptoms, but some men may get an itchy rash on the penis.