Burning, itching, and an unpleasant odor are just some of the common symptoms of vaginal infections. But treatments vary by condition, so it's important to know which type of vaginal infection you have. Vaginal infections, or vaginitis, are very common — so much so that most women will experience some form of vaginal infection or inflammation during their lifetime.

“To the gynecologist, vaginitis is a vaginal discharge with or without itching and burning, with or without an odor, says Gregory R. Moore, MD, MPH, an obstetrician-gynecologist and director of the University Health Service at the University of Kentucky in Lexington. Some women seem to be more prone to vaginal infections than others for reasons that are not entirely obvious, Dr. Moore says.

What Upsets the Normal Vaginal Balance

A healthy vagina has many bacteria and yeast. However, some things can disturb that healthy balance. These include:

• Douches 
• Hormone level changes
• Antibacterial 
• Vaginal intercourse
• Pregnancy and breastfeeding The Most Common Types of Vaginal Infections
  There are three very common types of vaginal infections, says Cynthia Krause, MD, assistant clinical professor of obstetrics and gynecology at Mount Sinai School of Medicine in New York City.
  • Yeast infections. The most common type of vaginitis, a yeast infection is caused by one of the many species of fungus known as Candida. Candida live naturally in your body in small numbers, including in the vagina, and usually don't cause any harm.
    However, Candida thrive in a warm, moist, airless environment and, under those conditions, can grow in number, causing a vaginal infection. Dr. Krause says, “There are many species of yeast or Candida — Candida is the most common.”
    Symptoms of a vaginal yeast infection include a thick, white discharge that some women describe as resembling cottage cheese. Yeast infections also can cause vaginal infection and redness of the vulva (the lips of the external female genital area) and vagina.
  • Bacterial vaginosis. Along with yeast, “friendly” bacteria called lactobacilli live in the vagina. When the number of lactobacilli gets too low, it can trigger a condition called bacterial infection. 
    Why bacteria levels change is not known, but the normal lactobacilli can be replaced by other infection-causing bacteria. “Gardnerella is the bacteria most often associated with bacterial vaginosis,” Krause says. “It is the lack of lactobacilli and overgrowth with these other bacteria that cause the symptoms of infection.”
    With bacterial vaginosis, a woman may see a thick or whitish discharge or one that is slippery and clear. It is not likely to itch or burn. A fishy odor may be noticeable, especially during intercourse. Trichinosis. “Of the three most common vaginal infections, trichomonas vaginitis is the only one that is a true sexually transmitted infection,” Krause says. Commonly called “trich,” it is caused by a single-celled parasite, trichomonas vaginalis, and is passed from partner to partner during intercourse.
  • The symptoms of trichomonas vaginitis are similar to other vaginal infections: burning, irritation, redness, and swelling of the vulva, with a yellow-gray or greenish vaginal discharge, possibly with a fishy odor. Some women also experience pain during urination.
  Other Vaginal Infections and Conditions
  Other common vaginal infections and causes of vaginal itching include:
  
  
  • Chlamydia vaginitis. Chlamydia, is a sexually transmitted disease that can cause inflammation of the vagina. Some women will have a discharge with chlamydia and some will not. A more common symptom is bleeding, especially after intercourse. “Sexually active women up to age 26 should be tested annually for chlamydia because it so often comes without symptoms and can linger and do a fair amount of damage to fertility,” Moore says.
  • Noninfectious vaginitis.Noninfectious vaginitis is when the skin around the vagina becomes sensitive to an irritant such as scented tampons, perfumed soaps, or fabric softeners. This is not an infection, and the solution is simple: “Not to be exposed to whatever you are having a reaction to,” Moore says. This is a condition in which women have chronic pain or discomfort of the vulva without a known cause. The symptoms are similar to vaginal infections: burning, stinging, rawness, soreness, and swelling. Symptoms may be constant or occasional.
  • Viral vaginosis. Viruses also can cause vaginal infections. Most viruses are spread through sexual contact. “The herpes simplex virus is a common cause of viral vaginosis,” Moore says. Symptoms include pain in the genital area from lesions or sores. Most of the time, you can see the sores on the vulva or vagina, but they can also be hidden and seen only during an examination by your gynecologist.