The vagina is an elastic, muscular passage that leads from the opening of the vulva to the uterus. The clitoris and labia form part of the vulva, just outside the vagina.The clitoris is a tissue cluster with numerous nerve endings making it extremely sensitive. It is located near the top of the inner labia - the fleshy, lip-like parts around the opening to the vagina.

The existence of the so-called G-spot is the subject of much controversy. In 1950, a German doctor called Ernst Grafenberg, claimed that, when stimulated, a specific area of the vaginal wall can trigger orgasm, but there is no consistent evidence to support that theory.

Studies show that there are many differences in the size and shape of vaginas and there is no common "standard". The height of a woman, or her age, may play a part in the dimensions of each individual's vagina.

Pelvic floor exercises, sometimes called Kegels, are contractions of the muscles that hold the bladder and urethra (the tube through which urine passes to the outside) in place. Imagine you are trying to stop yourself peeing. Doing these exercises can help incontinence by strengthening the 'sling-like' supportive muscles. These exercises can also stop the uterus and the bladder from sagging into the vagina. The NHS says strong pelvic floor muscles can increase sensitivity during sex and intensify orgasm.

Painful intercourse is fairly common, affecting nearly one out of four women at some time in their lives. If you regularly find sex painful you should go to your GP or a sexual health clinic for a checkup. There are a number of possible causes - from endometriosis or pelvic inflammatory disease (PID) to fibroids or recent childbirth. A lubricant may help if the vagina is dry. The problem can also be psychological. Lack of sexual arousal can cause painful sex. Try to relax and avoid sex when you are tired or anxious. Explore intimate experiences that are pain-free, such as massage.

The NHS suggests avoiding tight fitting underwear or tights, to help prevent vaginal thrush. As a thong is a small, close-fitting item, the friction of the fabric can aid the movement of bacteria or faecal matter to the vagina from the rectum. If hygiene is your top priority you may want to swap your thong for different underwear.

Toxic shock syndrome (TSS) is a rare but life threatening bacterial infection.  You may be at risk from TSS if you leave a tampon in the vagina for more than 8 hours. Watch for symptoms such as vomiting, a sunburn-like skin rash, diarrhoea, muscle aches, dizziness or confusion. If you develop a sudden high temperature and have one or more of these symptoms, get medical help immediately.

It is normal for the amount, colour and consistency of vaginal discharge to change depending on where you are in your menstrual cycle. At different times of the month discharge may be cloudy or clear and the consistency may range from sticky to creamy, or similar to egg whites. Healthy discharge does not usually have a strong smell or colour.

Any sudden change in discharge could indicate a vaginal infection. More discharge than usual, itchiness or a change in smell may indicate bacterial vaginosis (BV) or thrush. BV can be triggered by an upset in the pH balance of the vagina caused, for example, by vaginal sprays, perfumed soaps and sex with a new partner. Thrush often occurs when taking antibiotics.

If you have had a baby by caesarian section it does not necessarily mean you must deliver all future babies that way. In fact, most women who have had a caesarian section can have a vaginal delivery for their next child. Talk to your doctor or midwife about the best option.