Vaginal discharge is produced naturally by glands in the cervix and vaginal walls, and every woman has it. The fluid serves a basic housekeeping function: it carries away dead cells and bacteria, keeping the vagina clean and protected from infection. What changes, and what prompts most people to search this question, is when the amount, color, texture, or smell shifts in a way that feels unfamiliar. Those changes usually trace back to one of a few causes: normal hormonal fluctuations, a disrupted vaginal microbiome, an infection, or an outside irritant.
How Hormones Shape Normal Discharge
The consistency and volume of discharge shift throughout your menstrual cycle, driven mainly by two hormones: estrogen and progesterone. In the days after your period, discharge tends to be minimal, thick, white, and dry. As estrogen rises in the lead-up to ovulation, the cervix responds by producing more fluid. Just before ovulation, discharge turns clear, slippery, and stretchy, often compared to raw egg whites. This fertile-quality mucus lasts about three to four days and is designed to help sperm travel more easily.
After ovulation, estrogen drops and progesterone takes over. Discharge becomes thick and pasty again, then tapers off before your next period. These shifts are entirely normal and follow a predictable pattern once you know what to look for.
The Role of Vaginal Bacteria
A healthy vagina is home to a community of bacteria dominated by Lactobacillus species. These bacteria produce lactic acid, hydrogen peroxide, and antimicrobial compounds that keep the vaginal environment acidic, typically between a pH of 3.8 and 4.5. That acidity is what prevents harmful organisms from gaining a foothold. Lactobacillus also physically compete with invading microbes for space on the vaginal walls, acting as a living barrier.
When this bacterial balance is intact, discharge is usually clear to white, mild-smelling or odorless, and moderate in volume. When something disrupts that balance, the chemistry of the vagina shifts, and discharge often changes in noticeable ways.
Bacterial Vaginosis
Bacterial vaginosis (BV) is the most common cause of abnormal discharge. In one large population study, about 13.7% of vaginal tests came back positive for BV. It happens when the protective Lactobacillus bacteria are replaced by an overgrowth of anaerobic bacteria, organisms that thrive in low-oxygen environments. These bacteria form a thin film on the vaginal walls and produce chemical byproducts, including trimethylamine, which is responsible for the characteristic fishy smell.
BV discharge is typically thin, milky in consistency, grayish-white, and coats the vaginal walls evenly. The fishy odor is often more noticeable after sex or during your period. BV is not a sexually transmitted infection, though sexual activity can influence the bacterial environment. It raises vaginal pH above the normal acidic range, which is one reason it can make you more vulnerable to other infections at the same time.
Yeast Infections
Yeast infections, caused by an overgrowth of Candida fungus (most often Candida albicans), are nearly as common as BV. The same population study found about 11.2% of tests positive for yeast. Unlike BV, a yeast infection does not change vaginal pH. The environment stays at its normal acidic level, below 4.5, which is one way clinicians distinguish between the two.
The hallmark of a yeast infection is thick, white, clumpy discharge often described as resembling cottage cheese. It usually does not have a strong odor. The more bothersome symptoms tend to be intense itching, redness, swelling of the vulva, and sometimes small cracks or raw patches on the skin around the vaginal opening. Yeast overgrowth can be triggered by antibiotics, high blood sugar, a weakened immune system, or hormonal changes like pregnancy.
Sexually Transmitted Infections
Several STIs cause changes in discharge, and the appearance can vary depending on the infection.
Trichomoniasis is caused by a parasite and produces discharge that can be clear, white, yellowish, or greenish, often with a fishy smell. It tends to be thinner or greater in volume than normal. Other symptoms include genital itching, burning, redness, and discomfort when urinating. In the population study referenced above, trichomoniasis was far less common than BV or yeast, showing up in only 0.7% of tests, but it requires treatment to clear and can increase susceptibility to other STIs.
Chlamydia and gonorrhea can also cause abnormal discharge, sometimes yellowish or cloudy, though many people with these infections notice no discharge changes at all. That’s part of what makes them tricky: the absence of obvious symptoms doesn’t mean there’s no infection. Both can cause serious reproductive complications if left untreated, which is why routine STI screening matters even when discharge seems normal.
Discharge During Pregnancy
Increased discharge is one of the earliest and most persistent changes during pregnancy. The body ramps up production to create a stronger barrier between the vagina and the uterus, helping prevent infections from reaching the developing baby. This discharge, sometimes called leukorrhea, is typically thin, white or milky, and mild-smelling.
The volume increases as pregnancy progresses. In the final week or so before delivery, you may notice streaks of sticky, jelly-like pink mucus. This is the mucus plug that has been sealing the cervix throughout pregnancy, and its release signals that the body is preparing for labor. Discharge that turns green or yellow, develops a strong odor, or comes with itching or pain during urination can indicate an infection like yeast or BV, both of which are more common during pregnancy due to hormonal shifts.
Changes After Menopause
After menopause, estrogen levels drop significantly. Estrogen is what keeps the vaginal lining thick, elastic, and well-lubricated, so its decline leads to thinner, drier tissue and reduced discharge overall. The condition, sometimes called vaginal atrophy, can produce a thin, watery, sticky discharge that may appear yellowish or gray.
Lower estrogen also shifts the vaginal pH upward, making the environment less acidic and more hospitable to infections. This is why postmenopausal women are more prone to bacterial and yeast infections even without the hormonal cycling that triggers them in younger women.
Irritants and Allergic Reactions
Not all abnormal discharge is caused by an infection. The vaginal lining is sensitive to chemicals in everyday products. Scented soaps, vaginal sprays, douches, spermicides, sexual lubricants, scented wipes, and even certain laundry detergents or fabric softeners can trigger irritation or an allergic reaction. This is called non-infectious vaginitis, and it can produce increased discharge along with burning, redness, and itching.
Douching is one of the most common disruptors. It washes away the protective Lactobacillus bacteria and shifts the vaginal pH, creating conditions that make BV and yeast infections more likely. The vagina is self-cleaning; water alone on the external vulva is sufficient for hygiene. Products marketed as “feminine hygiene” solutions often cause more problems than they prevent.
What Different Colors and Textures Mean
- Clear to white, stretchy or slippery: Normal, especially around ovulation.
- White, thick, pasty: Normal before and after ovulation. If clumpy like cottage cheese with itching, likely a yeast infection.
- Thin, grayish-white, fishy smell: Characteristic of bacterial vaginosis.
- Yellow or green, possibly frothy: Could indicate trichomoniasis or another STI.
- Brown or blood-tinged: Often old blood from the end of a period or mid-cycle spotting. Persistent spotting outside your period warrants attention.
- Thin, watery, sticky: Common after menopause due to lower estrogen.
Color and texture are useful clues, but they overlap enough between conditions that appearance alone isn’t always enough to identify the cause. Persistent changes that last more than a few days, come with a strong odor, or are accompanied by itching, burning, or pelvic pain point toward something that needs a proper evaluation.