There's an entire industry dedicated to keeping women "fresh" down there.
Just spend five minutes in the feminine hygiene section of any major supermarket.
Next to important and necessary sanitary products like pads and tampons, you'll find a sizeable selection of deodorants, wipes and "intimate washes" designed to maximise "odour control" and maintain "lasting freshness".
Aside from being unnecessary, and in some cases, harmful, feminine care products tend to reinforce harmful ideas about vaginal discharge — that it is undesirable, if not unnatural, says Deborah Bateson.
"The feminine hygiene industry is, for profit, really shifting norms about what's normal," said Dr Bateson, associate professor at Sydney University and medical director of Family Planning NSW.
"Many women feel very anxious about something that's very normal, and [are made to] feel that we should all be smelling of rose petals or something."
Vaginal discharge plays an important role keeping the vagina healthy. Not only does it act as a lubricant during sex, it also works as a protective shield to keep infections away.
"It's important [women] know that vaginal discharge is normal, and that it's normal to have a bit of odour associated with it," Dr Bateson told ABC podcast Ladies, We Need to Talk.
By tinkering with the delicate balance of bacteria in the vagina, it's easy to disrupt the vaginal microbiome — and orchestrate the perfect conditions for an infection to flourish (which usually produces changes to vaginal discharge).
Instead of using products to minimise or conceal bodily functions, Dr Bateson said it is best to work out your "own normal" (spoiler alert: it varies) in order to know when something has gone awry.
Most of the time vaginal discharge is perfectly healthy. It serves as an important function of the reproductive system and helps keep the vagina clean.
Discharge contains a combination of dead cells and vaginal bacteria. It typically has a characteristic, but inoffensive, smell (which may be stronger in some women because of sweat glands in the pubic area), and is usually clear, creamy, or slightly yellow in colour.
"The normal amount of vaginal discharge that's produced every 24 hours is somewhere between 1 and 4 millilitres. So, a little less than a full teaspoon," Dr Bateson said.
"Some of that discharge is going to appear in our underwear as a normal part of life."
Discharge changes in colour, consistency and volume throughout the menstrual cycle in response to changing hormones.
"During the cycle … discharge starts off as dry and sticky. As we approach ovulation and there is an increase in oestrogen, the discharge changes consistency and becomes a little bit like an egg white … stretchy and slippery," Dr Bateson said.
"What that's doing is actually optimising the ability for sperm to swim through the mucus at the fertile time."
(Why do products exist to conceal discharge? Discharge is genius!)
"After the egg has been released and we pass the fertile phase, you get a decrease in oestrogen and an increase in progesterone, and the mucus changes again to become thick and sticky," she said.
Discharge is known to increase in volume during pregnancy (when oestrogen levels are higher), and dramatically decrease following menopause (when levels are lower).
"We know after menopause that amount of lubrication decreases and that can be incredibly painful for women," Dr Bateson said.
When something's up
The vaginal environment experiences all kinds of disturbances on a regular basis: sex, semen, contraceptives and antibiotics to name a few. Most of the time this disruption is temporary, and the vagina quickly restores itself.
Some changes to the composition of bacteria, however, can lead to an imbalance — and cause infection. A sudden change in vaginal discharge is often the first sign something's up.
Thrush is probably the most common vaginal infection, and is caused by an overgrowth of yeast, which lives naturally in the vagina in small numbers.
"It's sort of a cottage cheese type of discharge and is usually associated with an itch and inflammation. So, there can be redness and some real soreness," Dr Bateson said.
Another type of bacterial infection of the vagina is bacterial vaginosis (BV), which also occurs when the normal balance of bacteria in the vagina is out of whack.
"It is important to know the difference, because I certainly see women who have been treating their BV with thrush medications for a long time with no good effect, and vice versa," Dr Bateson said.
The main symptoms of bacterial vaginosis include a watery, greenish-greyish vaginal discharge, and an unpleasant "fishy" odour. In about half of cases, however, there are no symptoms.
Unlike thrush, which is unpleasant but causes no long-term health issues, bacterial vaginosis can increase a woman's risk of catching STIs, and has been linked to an increased rick of pelvic inflammatory disease, and early pregnancy loss.
Other reasons for changes in vaginal discharge include allergies and skin conditions of the vulva or vagina, along with sexually transmitted infections — though most bacterial STIs are asymptomatic in women, especially chlamydia.
"If you do notice an increase in odour or in the amount [of discharge], or an itch, go along and see your doctor," Dr Bateson said.
Say no to steaming
To reduce your risk of thrush, Dr Bateson said it was best to avoid wearing tight-fitting pants and synthetic underwear, which generally don't "allow the area to breathe and air to circulate".
The same, she said, goes for the daily use of panty liners, which are more suited for occasional use, such as leaking or spotting during your menstrual cycle.
"The daily wearing of panty liners is often a vicious cycle," she said.
"Women will notice they've got discharge, and they'll feel very anxious and worried about it.
"So, they'll start to use them, and sometimes that creeps up to wearing them every day, which can have a paradoxical effect of increasing the chance of thrush and also bacterial vaginosis."
To avoid upsetting the balance of good bacteria in the vagina, it's best to avoid douching, and any kind of "vagina steaming" (thanks, but no thanks, Gwyneth Paltrow).
Finally, when it comes to keeping it "fresh" down there, warm water and some soap — but only on the vulva — will do the trick, Dr Bateson said.
"We don't need to be putting any soap inside the vagina. Steer clear of that," she said.
"The vagina actually cleans itself."