Dr Suzy Elneil, consultant in urogynaecology and uroneurology at University College Hospital, London, has worked with a lot of women. "Like people, vaginas are completely individual," she says. "No two are the same."
Don't compare yourself to anyone else – what someone else's vagina looks like is normal for them, but won't necessarily be what's normal for you. Yours is unique.
The vagina and vulva
Some of a woman's sexual organs are inside the body, such as the womb, ovaries and vagina, and some are outside.
The external organs are known as the vulva. This includes the opening of the vagina, the inner and outer lips (labia) and the clitoris, which is located at the top of the vagina.
The vagina is a tube about 8cm (3in) long, which leads from the cervix (the neck of the womb) down to the vulva, where it opens between the legs.
The vagina is very elastic, so it can easily stretch around a man's penis or around a baby during labour.
"Vaginas vary in shape, size and colour," says Dr Elneil. "Some are small and ovoid [egg-shaped], some are large and cylindrical, and the colours can vary from light pink to a deep brownish red-pink. The important thing is that the vagina functions normally."
Pelvic floor exercises can help keep your vagina in shape. "These are good for maintaining good pelvic floor tone and can improve sexual function," she adds.
"Normal exercise also helps maintain good vaginal function, as walking and running helps the pelvic floor tone up and helps ensure good general health."
Find out about pelvic floor exercises, including how to do them.
Should I worry about the size of my labia?
Some women worry about the size of their labia (the lips outside the vagina), but there isn't usually any cause for concern. Labia vary from woman to woman, so don't judge yours by anyone else's standards.
"Large labia are only a medical problem if it affects the woman's working, social or sporting life," explains Dr Elneil.
"Size is really not a problem per se for most women. However, for cyclists, the length and size of the labia can affect their ability to sit comfortably on the seat, but this is a rare problem."
If you're worried, talk to your GP.
It's normal to have vaginal discharge (mucus or secretions), and the texture and amount of discharge can vary throughout your menstrual cycle.
If your normal vaginal discharge becomes different – for example, it changes colour or smells – this could be a sign of infection, so see your GP.
A healthy vagina shouldn't be itchy. Itching can be a sign of thrush or another infection, but it can also have other causes.
"Itching can be part of a generalised skin problem, such as eczema," Dr Elneil says. "Or it can be a sign of another condition, such as lichen sclerosus.
"All need treatment, so if the itch persists for more than a month, get it checked by a GP or gynaecologist. They need to see the vulva, perineum [between the vagina and anus] and the vagina directly."
Female genital mutilation
Female genital mutilation (FGM) is a procedure where the female genitals are deliberately cut, injured or changed, but there is no medical reason for this to be done. It is illegal in the UK, and is child abuse.
FGM is very painful and can seriously harm the health of women and girls. It can also cause long-term problems with sex, childbirth and mental health.
FGM is also known as "female circumcision", or "cutting", and by other terms like sunna, gudniin, halalays, tahur, megrez and khitan.
It is carried out for various cultural, religious and social reasons within some families and communities.
It is usually carried out on young girls between infancy and the age of 15, most commonly before puberty starts.
In some cases, girls and women may not remember having the FGM at all, especially if it was performed when they were a baby.
If you think FGM may have been done to you, or you are worried you or someone else may be at risk, you can get help from a specialist NHS gynaecologist or FGM service – ask your GP, midwife or another healthcare professional about services in your area.
Find out more about FGM.
You can also contact organisations directly, such as Equality Now, Daughters of Eve and NSPCC: FGM.
Find sexual health services near you.