Some might say there are no grey areas when it comes to an orgasm, but according to FEMAIL's sex and relationships expert Tracey Cox, many women aren't entirely convinced they've ever had one.
While some climaxes leave women in no doubt as to what has occurred, others are much more mild and subtle.
Here, Tracey reveals the extent of women's uncertainty around the big 'O', how to identify the real thing - and how to improve your chances of getting there, every time.
Tracey Cox reveals that 32 per cent of women are still unsure as to whether or not they have ever had an orgasm
In films and in porn, orgasms are nearly always earth-shattering, sheet-clutching, peel-me-off-the-ceiling affairs.
They're so powerful and unmistakable, you've got as much chance of 'missing' one as you have of not noticing Donald Trump sitting opposite you on the tube.
In reality, around one third of women say they don't know if they've ever had an orgasm.
US sex therapist Vanessa Marin reports that 32 per cent of the women who sign up for her orgasm workshop say they don't know if they're having orgasms or not.
I've counselled lots of women who think they've had an orgasm because they'll start off the sex session feeling turned on and finish it not wanting sex anymore.
But as any woman who has ever had good sex with a partner that didn't necessarily include an orgasm, this is no guarantee you've climaxed.
Your first orgasm
Most women have their first orgasm through masturbation, usually by using a vibrator.
Research also shows around 43 per cent of women have had an orgasm before their 18th birthday while 45 per cent have their first between the ages of 18 to 24.
(Don't feel weird if you vividly recall having an orgasm when you were really young: there is evidence of apparent female masturbation in the womb - yes really - and some girls orgasm by rubbing against things at a very early age.)
When we do experience orgasm for the first time, the majority of women are in no doubt at all about what's happened.
But not all. Some women's orgasms are so mild and subtle, they're left feeling confused over whether they've actually had one.
If all the orgasms you do 'see' (in TV shows, films, porn) are dramatic and intense, that vague, brief sensation seems hardly to qualify.
Tracey says that it is highly important to explore your body to achieve a climax
Not all orgasms feel the same but they do have certain things in common.
A sexual climax is the same as the climax of a novel or a film – it's the best bit, the peak of sexual pleasure.
Orgasms also always involve a release of pressure that's built up during stimulation.
But they vary widely in intensity – and this is where the confusion starts.
Not all orgasms feel the same
Some women always have spectacular, intense orgasms, others always have mild, subtle, disappointing ones.
Most of us have a mix: sometimes they're intense, other times they're 'Really? That was it?'
The reasons why orgasms differ in intensity are many: it depends where you are in your menstrual cycle, how much you've had to drink (too much and you've numbed the nerve endings), the mood you're in, past sexual experience, pelvic surgery, what's happening in your relationship, when you last had sex (and the list goes on).
How you have your orgasm – via a vibrator, tongue, fingers or penetration - also affects its intensity.
'The orgasm I have with my vibrator is far stronger than the orgasm I have when my partner stimulates me,' said one 32-year-old woman.
'For me, it's about control. If I'm in control of my orgasm I know just how to tease myself so I take a bit longer to get there and the feeling is more powerful.
'If he's in control, I'm slightly anxious. I worry he'll do something to put me off and that it's not going to happen.
'Men try to put off their orgasms for as long as possible but I don't know any woman who, when she feels an orgasm coming when she's with a partner, tries to stop it.'
Your first orgasm can feel like you need to pee
Lots of women stop themselves having a real orgasm because it feels like you need to pee.
The first time I had an orgasm I seriously thought that's what had happened.
I was about 15 and staying with my sister and discovered a personal massager, shoved in the back of a cupboard, while they were out.
I looked at it for a while, turned it on and watched it vibrate, then thought, 'Hmmm, I wonder what would happen if I just held it pressed against here for a second. Oh! That feels quite nice, I'll just do it for a little bit longer and . . . OH MY GOD! What the hell was that!'
I looked down at the floor in astonishment, convinced I'd had some totally bizarre bladder attack. I had no idea I'd just climaxed but I knew something had happened.
But that initial feeling of pressure building is rather similar to the feeling you get when you're dying to have a pee.
This is why I often recommend to women having trouble climaxing that they try to have their first orgasm while sitting on the loo and using a vibrator.
You won't pee when it happens (promise!) but it feels reassuring and you relax enough to let go.
Once you've had your first orgasm, you understand that feeling is normal and all part of it.
Practise makes perfect
The more you masturbate, the better and stronger your orgasms will be.
So if you're unsure of whether or not you've had one and only just started to explore sex, that could be why.
With experience, you learn what your body responds to best and what technique, speed and pressure suits you.
Most sex therapists recommend you teach yourself to orgasm by using a vibrator (it's by far the easiest way and requires no technique – just hold it against the vulva and voila!)
Lousy lovers could also be the reason for your lack of orgasms so make the effort to talk your partner through your needs
Once you've experienced one, you should then try using your fingers (with lots of personal lubrication) because it's a more partner friendly technique.
I've tried all that and still nothing
A tiny percentage of women 'miss' orgasms: their vaginal muscles contract but they don't register any sensation in their brain.
But this is rare and the cause it usually psychological and best solved by a professional therapist.
Figures are difficult to verify because women don't like talking about it but it's believed between five and ten per cent of (western) women have never climaxed.
The first step if you believe you are anorgasmic (you've never had an orgasm) is to get a physical check up.
Physical causes of anorgasmia include serious illnesses, pelvic trauma, pelvic surgery, hormonal imbalances and some medication.
But for a lot of anorgasmic women, the problem stems from a strict (often religious) upbringing that results in extreme sexual inhibitions.
Inhibitions stop us feeling relaxed enough to orgasm because we secretly believe sex and masturbation is 'dirty'.
Inexperience – not knowing your body or the function of the clitoris – is another factor.
But the biggest obstacle for having an orgasm with a partner is poor technique and men's lack of understanding about how the female sexual system works.
Lousy lovers don't help
'I got to the age of 44 without ever having an orgasm but thinking I had them regularly,' said one newly separated woman.
'My husband and I mainly had intercourse. I'd enjoy it but it wasn't until we split up and I slept with someone who really knew what they were doing with foreplay that I had a real orgasm.
'The first experience was like a fuzzy, pleasurable sensation. The second was like a rocket went off.'
There are still plenty of men out there who think their penis alone is capable of giving all women an orgasm.
Let's enlighten them.
Explain to our lovers that this would only happen if the clitoris was inside the vagina rather than an unhelpfully long distance away from the vaginal entrance.
The further away your clitoris is from your vaginal opening and the smaller it is, the more likely you are to suffer from anorgasmia.
Only 20 per cent of women can have an orgasm through penetration alone.
Despite people like me harping on (and on and on) about it, this fact still doesn't seem to have sunk in.
A lot of orgasm issues could be solved by women showing their partners how they orgasm when they are solo.
OMGYes.com is a fantastic website that shows - via video – twelve different ways to make a woman orgasm.
If you have any orgasm issues I'd highly recommend it (and even if you don't, check it out).
Also download Vanessa Marin's free online orgasm workshop: vmtherapy.com/how-to-orgasm
