Your vaginal pH is a key indication of your overall vaginal health. A balanced pH is usually between 3.8 and 4.2, but it can vary with age and where you are in your menstrual cycle.

pH is a measurement of how acidic or alkaline (basic) a substance is. The scale runs from 0–14. A pH of less than 7 is considered acidic, a pH of 7 is neutral, and a pH of more than 7 is basic.

A “normal” vaginal pH level is between 3.8 and 4.2, which is moderately acidic. However, what constitutes a “normal” pH level can vary slightly based on your stage of life.

For example, during your reproductive years (ages 15–49), your vaginal pH should be below or equal to 4.5. But before menstruation and after menopause, a healthy pH tends to be higher than 4.5.

An acidic vaginal environment is protective. It creates a barrier that prevents unhealthy bacteria and yeast from multiplying too quickly.

Disrupting the natural acidity of your vagina can cause discomfort and may even lead to infection.

Bacterial vaginosis (BV), for example, can develop in response to an overgrowth of certain bacteria. This can cause your vaginal pH levels to increase, making the vagina more alkaline.

BV is the most common vaginal infection in the United States. BV isn’t necessarily harmful in itself, but people who have this condition have an increased risk of developing more serious infections.

This includes:

Yeast infections, also known as candidiasis, are the second most common vaginal infection in the United States. They can cause vaginal pH levels to decrease, making the vagina more acidic.

An acidic environment typically doesn’t increase the risk of infection or disease. But it can affect your ability to become pregnant during penis-in-vagina sex.

Sperm thrive in an alkaline environment. The optimal pH for sperm to swim is between 7 and 8.5. Sustained acidity can make it difficult for sperm to reach or successfully fertilize an egg.

Usually, a sign of an underlying pH imbalance is when you experience an unexpected change in odor that lingers after a thorough wash or an odor that occurs alongside other unusual symptoms.

A healthy vulva and vagina can smell somewhat salty, sweet, or musky. You might notice a more metallic smell around your menstrual period. But if your vaginal area smells fishy or otherwise foul, it’s usually a sign of BV.

An uptick in vaginal discharge, change in texture, or change in color can also indicate an underlying pH imbalance. Yeast infections may cause a thick white discharge. BV is associated with watery gray or green discharge.

Other signs of a pH imbalance include:

Some pH fluctuations are expected. Menstrual blood, for example, is slightly alkaline. When blood flows through the vaginal canal, it increases the overall pH.

Antibiotics wipe out all bacteria. This includes the bacteria that cause illness and the bacteria you need to maintain a healthy, more acidic vaginal pH level.

Other disruptions are more unpredictable. Solo or partnered sexual activity can affect your vaginal pH with or without vaginal penetration, regardless of whether you use a condom or other barrier method.

Exchanging bodily fluids through genital-to-genital and oral-genital contact can encourage the growth of certain bacteria. Fingering can introduce bacteria, as can shared or improperly cleaned sex toys.

So-called “feminine” hygiene products, including scented sprays and suppositories, and practices like douching and steaming can also alter the vagina’s natural microbiome.

Mild irritation can be managed with certain lifestyle changes. Limiting time spent in damp or wet clothes, washing more frequently, and staying hydrated can help.

If you suspect BV could be to blame, you can use an at-home test to check for infection or make an appointment with a healthcare professional to discuss your symptoms.

Although some over-the-counter (OTC) products are marketed as effective BV treatments, the Food and Drug Administration (FDA) has not approved any OTC method for use.

Antibiotics aren’t always necessary — BV may resolve on its own — but they can help alleviate your symptoms and speed up recovery. Your clinician will likely prescribe one of the following:

  • metronidazole, which can be applied topically or taken as a pill
  • clindamycin, which can be applied topically, inserted as a suppository, or taken as a pill
  • tinidazole, which is taken as a pill
  • secnidazole, which is taken as a powder mixed with food

You can also use an at-home test to check your overall pH balance. These tests don’t check for infection specifically, but the results can be used to help narrow down the potential cause.

If you suspect a yeast infection, you may be able self-treat with an OTC antifungal cream, ointment, or suppository. More severe cases may benefit from prescription medication like fluconazole (Diflucan). If this is your first yeast infection, you should see a doctor.

  • Wash your vulva, not your vagina: Your vagina is self-cleaning, but your vulva can use a little help. Wet a washcloth with warm water and gently clean each fold of your external genitalia. Avoid douches and other internal “cleansers.”
  • Stay dry: Avoid spending extended periods of time in damp underwear or swimsuit bottoms. Wash up, pat yourself dry, and change into something clean and dry as soon as possible.
  • Let your vulva and vagina breathe: Stick to cotton and other breathable materials when selecting underwear. You might also size up on pants, shorts, and other bottoms for a looser fit or select clothes with an airy silhouette.
  • Pay attention to how you wipe: Always wipe from front to back to prevent fecal bacteria from spreading to your vagina.
  • Consider your probiotic intake: Probiotics may help reduce symptoms of BV and prevent recurrent BV infections. Lactobacillus strains, in particular, can help speed up recovery.
  • Practice safer sex: Using a condom or barrier method can help reduce the risk of STIs, and regular STI testing can help you stay on top of your status.

If you’re uncomfortable with at-home testing or unsure of your symptoms, it’s important to consult with a healthcare professional.

The following symptoms typically require medical intervention:

  • burning, itching, or pain
  • fishy or foul vaginal odor
  • foamy, frothy, or increased vaginal discharge
  • gray, yellow, or green vaginal discharge

Your clinician will ask about your symptoms, your medical history, and recent sexual activity to help identify the underlying cause.

They may perform a pelvic exam and swab inside the vagina to take a fluid sample for lab testing. They may also ask for a urine sample.

Can you fix your pH balance overnight?

It is not possible to balance your vaginal pH overnight.

How do you check your vaginal pH level?

You can purchase an OTC test kit to measure the pH of your vaginal secretions, but this typically isn’t necessary to detect a yeast infection or BV.

Remember, your vaginal pH can fluctuate for a number of reasons. A lower or higher than-expected pH isn’t an automatic indication of infection or a sign that something is wrong.

Is there a natural way to balance your vaginal pH?

Eating fermented foods with live probiotics can help increase the amount of healthy bacteria in your body. Probiotic supplements with Lactobacilli may be especially beneficial.

Your vaginal pH depends on a variety of factors, including your age, your overall health, and your recent activity levels.

If you’re concerned about a change in vaginal odor, changing into a fresh pair of underwear after a bath or shower may do the trick.

Consult with a healthcare professional if the odor lingers or occurs alongside other unusual symptoms.

Tess Catlett is a sex and relationships editor at Healthline, covering all things sticky, scary, and sweet. Find her unpacking her inherited trauma and crying over Harry Styles on Twitter.