What is normal vaginal pH?

This article was professionally consulted with Specialist Doctor I Truong Nghia Binh - Obstetrician - Gynecology Department - Vinmec Da Nang International General Hospital.

Maintaining the pH balance of the vagina is essential. A pH below 7 is acidic, while a pH above 7 is alkaline. Normal vaginal pH is usually below 4.5. The lower the number, the more acidic the vaginal environment will be.

pH is a measurement of how acidic or alkaline a substance is. The scale runs from 0 to 14. A pH less than 7 is considered acidic and a pH greater than 7 is alkaline.
The pH of the vagina - whether it is acidic or alkaline plays an important part in determining if it is healthy or not.

A normal vaginal pH is between 3.8 and 4.5, with moderate acidity. However, there is variation in the normal pH of the vagina depending on life stage.
During a woman's reproductive years (ages 15 to 49), vaginal pH should be 4.5 or less. But before menstruation and after menopause, normal pH levels tend to be higher than 4.5.
An acidic vaginal environment will have a protective function. It creates a barrier that prevents bad bacteria and yeast from multiplying too quickly and causing infection.
A high vaginal pH - above 4.5 - provides the perfect environment for pathogenic bacteria to grow. A high vaginal pH puts you at risk for these infections:
Bacterial vaginosis (BV) is an overgrowth of bacteria that causes a fishy odor, along with colored vaginal discharge unusual gray, white or yellow. It can also lead to vaginal itching and burning while urinating. BV is not necessarily harmful by itself, but women who have it are at increased risk for more serious infections such as human papillomavirus (HPV), herpes simplex virus, and HIV. Trichomonas (trich) is a sexually transmitted disease (STD) caused by the parasite Trichomonas vaginalis. Trich usually causes no symptoms in the majority of people who are infected, but it can increase the risk of other, more serious STDs, like HIV. An acidic vagina usually does not cause disease. But if the acidity increases too much, it can reduce fertility. Sperm thrive in an alkaline environment. The optimal pH for them to swim is between 7.0 and 8.5. During sex, the pH inside the vagina temporarily increases, making the normally acidic environment more alkaline to protect the sperm so they can reach the egg.

Unprotected sex. Semen is alkaline, which can promote the growth of certain bacteria. Antibiotics: These drugs not only kill the disease-causing bacteria but also the good bacteria that maintain a healthier, acidic, vaginal pH level. Douching: About 20% of women regularly rinse their vagina with a mixture of water and vinegar, baking soda, or iodine. Douching not only increases vaginal pH, but also increases the growth of harmful bacteria in general. Menstrual cycle: Menstrual blood is alkaline and raises the pH in the vagina. When blood flows through the vagina and is absorbed into a tampon or pad, it can raise the pH level of the vagina.

Bad or fishy odor Unusual white, gray or green mucus Vaginal itching Burning when urinating.

If you have symptoms of vaginitis or another condition related to high vaginal pH, see your doctor.
To treat bacterial vaginosis or trichomoniasis, your doctor may prescribe one of these antibiotics with a pill or cream:
Clindamycin (Cleocin) for BV Metronidazole (Flagyl) for BV or trichomonas Tinidazole (Tindamax) for BV or trichomonas

When having sex, use a condom. The barrier not only protects from STDs but also prevents alkaline semen from disrupting vaginal pH levels. Take probiotics to restore the balance of healthy bacteria. Do not douche: It can increase the pH level in the vagina. The vagina can naturally clean itself. Only wash the outside of your vagina with mild soap and water when you shower. Eat yogurt: In addition to helping to get enough calcium and vitamin D daily, yogurt is a rich source of beneficial bacteria species of Lactobacillus.