16 Frequent Causes of Bacterial Vaginosis

2. Douching

Douching means rinsing the inside of your vagina with water or a liquid solution. Some people use store-bought products, while others use homemade mixtures. Douching can upset the natural balance inside your vagina.

Your vagina contains both healthy and harmful bacteria. The healthy bacteria keep the area slightly acidic, which controls the growth of harmful bacteria. When you douche, you wash away some healthy bacteria, which raises vaginal pH and allows harmful bacteria to grow, which can lead to bacterial vaginosis.

Douching can also irritate the vaginal lining, which makes it easier for bacteria to multiply. If you already have BV, douching can worsen symptoms or cause the infection to return after treatment. Many people douche to reduce odor or discharge, but these symptoms often signal an imbalance that needs proper care, not rinsing. Washing the outer genital area with mild soap and water is enough, as the vagina cleans itself naturally without internal washing.

3. Switching Washing Powder

Switching washing powder changes the chemicals that touch your skin. Some detergents contain fragrances, dyes, and strong cleaning agents, which can irritate the sensitive skin around your vagina. Irritation can upset the natural balance of bacteria in that area.

When harsh residue stays in your underwear, it may affect that balance and raise your risk of bacterial vaginosis. Even small amounts of leftover detergent can cause problems. Tight clothing and heat can press these chemicals against your skin for hours, which leads to itching, burning, or unusual discharge.

Powders labeled as scented, brightening, or extra strength often contain more additives. Liquid detergents can also cause issues if heavily fragranced. Using too much detergent or skipping an extra rinse cycle can leave more residue behind. Underwear made of breathable fabrics helps reduce moisture and irritation, but detergent buildup can still affect your skin.

4. Some Shower Gels and Other Products

Some shower gels, soaps, and bath products can upset your vagina’s natural balance. Many contain fragrance, dyes, or strong cleaning agents that irritate the delicate skin around the vulva. Harsh products can change the pH level and reduce helpful bacteria. When this balance shifts, harmful bacteria can grow more easily, which may lead to bacterial vaginosis.

Even “gentle” products can cause problems if used too often. Washing the inside of your vagina or using scented products in that area disturbs its natural environment. The vagina cleans itself, so it does not need special soaps inside.

Tight clothing washed in strong detergent can also irritate the area. When the skin becomes irritated, it may feel itchy or sore, which makes it easier for bacteria to grow out of balance. Simple, mild, and fragrance-free products are less likely to disrupt your natural bacteria.

5. Tampon Use

Tampons do not directly cause bacterial vaginosis, but certain tampon habits can upset your vagina’s natural bacterial balance. Leaving a tampon in for too long may change moisture and pH levels. You increase your risk when you leave a tampon in for more than eight hours or choose a higher absorbency than necessary.

You also raise your risk when you forget to change it regularly or switch often between tampons and other internal products. Tampons absorb menstrual blood and some natural fluids that protect your vagina. When protective fluids decrease, harmful bacteria may grow more easily.

Scented tampons can also irritate sensitive tissue. Fragrance and added chemicals may disrupt your normal pH and lead to irritation. Changing tampons regularly and choosing the lowest absorbency you need can help maintain your vaginal balance.

6. Overuse of Vaginal Hygiene Products

Extra washing does not keep your vagina cleaner. Overusing vaginal hygiene products can upset your natural bacterial balance, which leads to bacterial vaginosis. Your vagina cleans itself. When you use scented soaps, bubble baths, vaginal sprays, or wipes, you may remove helpful bacteria. Without enough “good” bacteria, other bacteria can grow too much.

Douching pushes water or cleaning solutions into the vagina, and this disturbs the normal environment and makes it easier for harmful bacteria to take over. Products that often cause problems include scented soaps or body washes used on the vaginal area and feminine sprays or deodorants.

Scented pads or tampons, bubble baths and bath oils, vaginal cleansing wipes, and douching solutions also increase irritation and disrupt balance. Even products labeled as “gentle” or “for sensitive skin” can cause problems if used often. The skin around your vagina is delicate, and strong fragrances and chemicals may cause irritation, dryness, and changes in bacteria levels.

7. New Sexual Partners

Starting a relationship with a new sexual partner can increase your risk of bacterial vaginosis. A new partner introduces different bacteria into your vagina, which can upset the balance between healthy and harmful bacteria. Your vagina normally contains protective bacteria that keep the pH level slightly acidic, which limits harmful germs.

Semen and new genital contact can change your vaginal pH, even if you do not notice symptoms right away. Having more than one partner during the same period raises risk, as each partner brings a unique mix of bacteria. Using condoms can lower the chance of this imbalance.

Women who have never been sexually active rarely develop bacterial vaginosis, which shows a clear link between sexual activity and this condition. Starting a new sexual relationship does not guarantee you will develop bacterial vaginosis, but it increases the likelihood that your vaginal environment may change in ways that allow harmful bacteria to grow.

8. Fabric Allergies

Fabric allergies can irritate the skin around your vulva. When your skin reacts to certain materials, it may become red, itchy, or swollen, which upsets the natural balance of bacteria in your vagina. Tight clothing made from synthetic fabrics like nylon or polyester traps heat and moisture.

Warm, damp areas allow harmful bacteria to grow more easily, which increases your risk of bacterial vaginosis. Laundry products such as detergents, fabric softeners, and dryer sheets often contain fragrances and chemicals that leave residue in your underwear and irritate sensitive skin.

Itching, burning, or a rash after wearing certain clothes signals irritation. Scratching or ongoing irritation can weaken your skin’s natural barrier, which makes it easier for bacteria to multiply. Choosing breathable cotton underwear and washing clothes with mild, fragrance-free detergent can reduce irritation.

9. STI Infection

Sexually transmitted infections (STI) can upset your vagina’s natural bacterial balance. Harmful germs entering your body during sexual contact change the mix of good and bad bacteria, which makes it easier for bacterial vaginosis to develop.

Some infections, such as chlamydia, gonorrhea, and trichomoniasis, irritate the vaginal lining and raise vaginal pH. A higher pH allows harmful bacteria to grow faster than healthy bacteria. Many STIs stay silent at first, but they still affect your vaginal environment. Even without clear signs, the infection can disturb the balance and increase your risk of bacterial vaginosis.

If you have bacterial vaginosis, you also face a higher risk of getting an STI. Infections can pass through vaginal, oral, or anal sex. Treatment usually involves antibiotics or other antimicrobial drugs, depending on the infection, which target the harmful germs. Until the infection clears, the vaginal imbalance may persist and continue to trigger bacterial vaginosis.

10. Smoking and Drinking Alcohol

Smoking upsets the natural balance of bacteria in your vagina. The chemicals in tobacco lower oxygen levels in vaginal tissue, which reduces helpful bacteria and allows harmful bacteria to grow. Nicotine and other toxins weaken your immune system, which makes it harder for your body to keep bacteria in check. This shift raises your risk of bacterial vaginosis and makes it more likely to return after treatment.

Drinking alcohol may also play a role. Heavy or frequent drinking affects your immune response and hormone levels. Alcohol misuse harms many parts of your body, including systems that fight infection. Alcohol use can link to behaviors that increase BV risk, such as unprotected sex or multiple partners. Alcohol does not directly cause BV, but frequent smoking and drinking can increase the risk of imbalance and repeated vaginal infections.

11. Sexual Behavior

Your sexual activity can affect the balance of bacteria in your vagina. Bacterial vaginosis is not always classified as a sexually transmitted infection, but sexual behavior can raise your risk. Having a new sexual partner or multiple partners increases your risk because each partner introduces different bacteria, which can upset the normal balance between helpful and harmful bacteria.

The more often your vaginal bacteria encounter new bacteria, the harder it is for your body to keep a stable balance. Not using condoms may also raise your risk, as semen can change the natural acidity of your vagina, making it easier for harmful bacteria to grow. Sex between women can spread bacteria linked to bacterial vaginosis. Sharing sex toys or direct contact between vaginal fluids can pass bacteria from one partner to another.

12. Eating Too Many Refined Carbohydrates

Refined carbohydrates include foods made with white flour and added sugars, such as white bread, pastries, white rice, sugary cereals, soda, and candy. These foods give you quick energy but very little fiber or key nutrients. When you eat a lot of refined carbs, your blood sugar rises fast, and your body releases insulin to lower it.

Frequent spikes in blood sugar can affect many systems in your body, including the balance of bacteria in your gut and vagina. Your vagina needs a healthy mix of bacteria, mainly lactobacilli, to stay balanced. Diets high in sugar may support the growth of harmful bacteria and make it harder for protective bacteria to do their job. Over time, this imbalance can raise your risk of bacterial vaginosis by changing the natural environment in your vagina.

13. Drug Use

Drug use can change the natural balance of bacteria in your vagina. When this balance shifts, harmful bacteria can grow faster than healthy bacteria. Some substances affect your immune system. Recreational drugs such as cocaine or methamphetamine can weaken your body’s defense system, which makes it harder to keep vaginal bacteria in balance.

Certain prescription drugs can also raise your risk. Broad-spectrum antibiotics kill harmful bacteria but also reduce the healthy bacteria in your vagina. Without enough healthy bacteria, other types can grow out of control. Hormonal medications may also play a role by changing your hormone levels, which can affect vaginal pH and make it easier for harmful bacteria to grow.

Injecting drugs brings added risk. Shared needles increase the chance of infections, and overall poor health from drug use can disrupt normal body systems, including those that help maintain healthy vaginal bacteria.

14. Failing to Urinate After Sex

When you do not urinate after sex, bacteria can stay near the opening of your vagina and urethra. Sex can move bacteria from the skin or anus closer to these areas. If you wait too long to pee, those bacteria have more time to grow. Bacterial vaginosis happens when the balance of normal vaginal bacteria shifts.

You naturally have both helpful and harmful bacteria in your vagina. If harmful bacteria grow too much, you may develop BV. Urinating after sex helps flush out bacteria from the urethra. This step mainly lowers the risk of urinary tract infections, but it can also support better genital hygiene.

When bacteria linger around the vaginal area, they may disturb the normal balance over time. Failing to urinate after sex does not directly cause BV on its own. However, it can add to other risk factors, such as unprotected sex or having new or multiple partners.

15. Post-Surgical Infection

Surgery can change the balance of bacteria in your body. When you have a procedure near your pelvic area, harmful bacteria may grow more easily, which raises your risk of bacterial vaginosis. A surgical site infection occurs when germs enter the body through a cut made during surgery. These infections often affect the skin, but bacteria can also spread to nearby areas and shift the natural balance of vaginal bacteria.

You may receive antibiotics before or after surgery to prevent infection. While these drugs kill harmful bacteria, they can also reduce healthy bacteria. When helpful bacteria decrease, other bacteria can grow too much and cause symptoms.

Your immune system may feel weaker while you recover. Stress, healing wounds, and changes in hygiene routines can also affect your vaginal health. If you notice symptoms after a procedure, pay attention to changes in discharge, smell, or comfort. Early care can help manage both surgical infections and related vaginal changes.

16. Antibiotic Use

Antibiotics treat bacterial infections but can upset the natural balance of bacteria in your body. When you take antibiotics for conditions like sinus, urinary tract, or skin infections, the medicine targets harmful bacteria and also reduces helpful bacteria that protect your vagina.

This reduction in good bacteria can make you more likely to develop symptoms. Your vagina normally contains more “good” bacteria than “harmful” bacteria. These good bacteria help keep the area slightly acidic, which limits the growth of unwanted germs.

When antibiotics lower the number of protective bacteria, harmful bacteria can grow more easily, which can lead to bacterial vaginosis. You may notice thin discharge, a fishy odor, or mild irritation. Broad-spectrum antibiotics increase the risk because they act against many types of bacteria at once. Repeated or long-term use disturbs the balance further.