An orgasm is the body's way of rewarding us for sex. However, if you're sleepy, unfit, have a poor diet, drink, smoke or take drugs, these can all affect your ability to come.
You may also find climax tricky because you're not really ready for sex; because you're nervous about getting pregnant (check out our contraception guide); or because you've had a traumatic experience. If so, see your GP as you can then be referred to the most useful service.
Even if you're not ready to have an orgasm with a partner, it's entirely possible - and often a lot easier - to have an orgasm on your own. The better you know your own body, the easier it will be for you to climax with a partner so it's good for you.
A healthy body leads to healthy climax.
The four stages of orgasm:
Blood flows to your lips, nipples and bits. Your genitals will swell and darken in colour, feeling tingly. Women may start to get wet, and men may leak precum from the penis; your pulse and breathing quicken and you may become flushed.
Top Tip: If you don't get wet, Durex Play lubricant can help make this stage go more smoothly, by providing moisture to make foreplay comfortable and give the body a bit of a kick start.
In women, the top of the vagina opens up, and womb shifts in preparation to receive sperm. Blood rushes to the chest making nipples harden and breasts swell. The clitoris pulls back against the pubic bone and the hood (like a male foreskin) slides back to expose the tip. For men, the urethral sphincter (hole in the centre of the glands) contracts to stop urine from leaking out and the muscles at the base of the penis start pulsing. The testicles tighten.
Men ejaculate and women's vaginal muscles contract and release spasmodically (at 0.8 second intervals), the heartbeat and breathing rate increase and the anus goes into spasm. After climax, the clitoris and head of the penis can become painfully sensitive to touch.
This is when the body relaxes after orgasm and gets back to normal. Men may fall asleep (as may women) or you may feel a real need to snuggle.