A slightly tangy or sour vaginal smell can be completely normal — but it can also be a sign that something in your body’s balance has changed. Many women notice a sour odor after sweating, sex, or during certain points in the menstrual cycle, and immediately worry. The truth is: vaginal odor varies from person to person, and it can shift throughout the month.

So what does it mean when your vagina smells sour? Below are four real and common causes, plus clear signs of when you should see a doctor.

---

1) Normal Vaginal pH and Healthy Bacteria

One of the most common reasons for a sour smell is simply a healthy vaginal environment. The vagina is naturally acidic, usually with a pH between 3.8 and 4.5. This acidity is maintained by beneficial bacteria (mainly Lactobacillus) that protect against harmful germs.

Because of that acidity, a healthy vagina can smell:

• Tangy

• Sour

• Slightly “fermented” (similar to yogurt)

If you don’t have itching, pain, burning, or unusual discharge, a mild sour scent may just be your body doing its job.

SEO Tip: A sour vaginal odor alone doesn’t always mean infection — your pH may be normal.

---

2) Sweating, Tight Clothing, and Moisture Build-Up

The genital area has many sweat glands, and sweat combined with bacteria can create a stronger sour odor, especially in hot weather or after exercise. This is even more likely if you wear:

• Tight underwear

• Synthetic fabrics

• Leggings for long hours

• Wet swimsuits too long

When moisture gets trapped, bacteria can multiply and odor becomes more noticeable — even if you don’t have an infection.

What helps:
Choose breathable cotton underwear, change out of sweaty clothes quickly, and keep the area dry.

---

3) Semen, Sex, and Hormonal Changes

Sex can temporarily change vaginal odor — especially if semen is involved. Semen has a higher pH (more alkaline), which can disrupt the natural acidic balance and cause odor changes for 24–48 hours.

Hormonal shifts can also affect smell, including:

• Ovulation

• Before or after your period

• Pregnancy

• Birth control changes

You may notice a sour smell mixed with a stronger “musky” scent during those times.

Important: If the odor goes away after a day or two and there are no other symptoms, it’s typically not a concern.

---

4) Infection or Imbalance (BV or Yeast)

If the sour smell becomes strong, unpleasant, or persistent, it may be due to an imbalance or infection. Two common causes include:

Bacterial Vaginosis (BV)

BV occurs when the vaginal bacteria balance shifts and harmful bacteria overgrow. BV is often linked to:

• Fishy or strong odor

• Thin gray/white discharge

• Odor that worsens after sex

Yeast Infection

A yeast infection may cause odor changes, though it’s more known for:

• Itching and irritation

• Thick white discharge (cottage-cheese-like)

• Burning during urination or sex

While BV is more likely to cause a noticeable odor, both conditions should be treated properly — and self-treating without knowing the cause can make symptoms worse.