Although the genitals are a key part of sex, its pleasurable sensations involve many parts of the body. Pleasurable sex heavily depends on the brain, which releases hormones that support sexual pleasure and interpret stimulation as pleasurable.
One 2019 study suggests that the brain could be the most important sexual organ. The author found that orgasm is a heightened state of sensory awareness that can trigger a trance-like state in the brain.
In this article, we examine the effects that sex has on the body and the brain, as well as how these effects make sex feel good. We also take a look at why sex might not feel good.
Effects of sex on the body
In the 1960s, sex researchers William Masters and Virginia Johnson identified four distinct phasesof sexual arousal, each with unique effects on the body.
Their research has led to the common use of these four categories to explain sexual response:
1. Desire or excitement
The pleasurable sensations a person feels during sex come from many different parts of the body.
During the desire phase, the tissue in the penis, vagina, pelvis, vulva, and clitoris fill with blood. This increases the sensitivity of nerves in these areas of the body.
This blood flow also creates a fluid called transudate, which lubricates the vagina.
Muscles throughout the body begin contracting. Some people breathe more rapidly or develop flushed skin due to the increased blood flow.
During the plateau stage, a person’s arousal continues to intensify. The vagina, penis, and clitoris become more sensitive.
A person may experience variations in sensitivity and arousal during this period. Arousal and interest may decrease, intensify, then decrease again.
With the right stimulation and the right mental state, a person may have an orgasm.
For most females, clitoral stimulation is the fastest, most effective path to orgasm. For some, it is the only path to orgasm. Males may need prolonged stimulation of the shaft or head of the penis.
Most males ejaculate during orgasm, but it is possible to have an orgasm without ejaculating. Some females also ejaculate during orgasm, though the content of this fluid remains the subject of scientific discussion.
Both males and females experience intense muscle contractions during orgasm.
Males experience these contractions in the rectum, penis, and pelvis, while females experience them in the vagina, uterus, and rectum. Some people experience contractions throughout the entire body.
After orgasm, the muscles relax, and the body slowly returns to its pre-arousal state.
This process is different for males and females. Although most males cannot have an orgasm immediately after ejaculating, many females can.
During the resolution stage, most males and many females experience a refractory period. During this time, the person will not respond to sexual stimulation.
Some researchers have proposed alternative models for resolution.
Karen Brash-McGreer and Beverly Whipple’s circular model suggests that a satisfying sexual experience for a female can promptly lead to another such experience.
Rosemary Basson proposes a nonlinear model of female sexual response. Her model emphasizes that females have sex for many reasons, and that their sexual response may not proceed according to predictable stages.
The clitoris is, for most females, the point of origination for sexual pleasure. It has thousands of nerve endings, making it highly sensitive. Portions of the clitoris extend deep into the vagina, allowing some women to get indirect clitoral stimulation through vaginal stimulation.
For men, the head of the penis is similar to the clitoris in that it is often the most sensitive area.
Effects of sex in the brain
The body releases a number of hormones, including norepinephrine, during sexual stimulation.
For sex to feel pleasurable, the brain has to interpret sexual sensations as pleasurable.
Nerves in sexual areas of the body send specific signals to the brain, and the brain uses those signals to create various sexual sensations.
Neurotransmitters are chemical messengers that help the brain communicate with other areas of the body. Several neurotransmittershave a role in sexual pleasure:
- Prolactin levels rise immediately following orgasm. This hormone might be related to reduced sexual response, which may explain the refractory period.
- Dopamine is a hormone linked with motivation and reward. It increases sexual arousal, and the body secretes it during the desire stage.
- Oxytocin, also known as the love or bonding hormone, promotes feelings of intimacy and closeness. The body releases it after orgasm.
- The body releases serotonin, which supports feelings of well-being and happiness, during the arousal phase.
- Norepinephrine dilates and constricts blood vessels, making the genitals more sensitive. The body releases this during sexual stimulation.
Reasons that sex might not feel good
Sex is not pleasurable for everyone. In fact, some people feel pain during sex. This is much more prevalent in females.
Around 75% of females report experiencing pain during sex at some point during their lives.
Around 10–20% females in the United States experience regular sexual pain, or dyspareunia.
Some common reasons for sexual pain in females include:
- vulvodynia, a chronic condition that causes itching, as well as burning pain during and after sex
- vaginal infections such as yeast infections
- muscle injuries or dysfunction, especially pelvic floor injuries after childbirth
- hormonal changes, which may cause vaginal dryness and pain
Males can also experience pain during sex. Some common causes include:
- structural abnormalities in the penis, such as phimosis
- problems with the prostate, such as prostatitis
People who identify as asexual may not desire sex or experience pleasure from it.
People who identify as demisexual may only experience sexual pleasure in limited contexts, such as when they feel in love with a partner.
Some other factors that can affect sexual pleasure across all genders and sexual orientations include:
- insufficient lubrication, which can cause sex to be painful
- a history of trauma or abuse, which can make sex feel threatening or painful
- lack of arousal
- boredom with sex or one’s partner
- sexual interactions that do not conform to a person’s specific sexual desires or interests
- sexually transmitted infections
See a doctor about sexual pain or displeasure if:
- the pain persists over time or gets worse
- management strategies, such as using more lubrication or changing positions, do not work
- pain occurs with other symptoms, such as pain when urinating or unusual vaginal bleeding
- pain follows an injury, childbirth, or a medical procedure
Some people, especially females, report that doctors dismiss sexual pain or tell them that it is all in their heads. People who do not get sensitive, responsive care from a healthcare provider should switch providers or seek a second opinion.
Sex does not have to hurt, and there is almost always a solution. A knowledgeable and compassionate provider should be committed to diagnosing and treating the issue.
Tips for pleasurable and safe sex
Getting regular exercise may improve the blood flow needed to get and maintain an erection.
Clear communication with a trusted partner can make sex more pleasurable by helping the partners discuss their needs openly.
A 2018 study that found a significant orgasm gap between males and females also identified strategies linked with more orgasms — and potentially more pleasurable sex — for females. These strategies include:
- oral sex and manual genital stimulation, such as fingering
- sex that lasts longer
- relationship satisfaction
- discussing fantasies and sexual desires
- expressing love during sex
Although estimates of the precise number vary, most females cannot orgasm without clitoral stimulation.
For some females, indirect stimulation from certain sexual positions, such as being on top, is enough. Others need direct, prolonged stimulation during or separate from intercourse. This is normal and typical, and females should not feel ashamed of needing or asking for clitoral stimulation.
Males may enjoy sex when it lasts longer, both because this allows pleasure to build over time and because it increases the odds that female partners will have time to orgasm. Deep breathing may help a male delay ejaculation, as can slowing down when the sensations become too intense.
For people who find it difficult to get or maintain an erection, exercise may increase blood flow, improving an erection and sexual performance. Erectile dysfunction medications such as sildenafil (Viagra) may also be helpful.
People may find that using a sexual lubricant decreases friction, improving sex. Lubricants are available to buy in many stores and online.
Pelvic floor exercises strengthen the muscles that play a role in orgasm, potentially helping both males and females have stronger orgasms and better control over the timing of orgasm.
To exercise the pelvic floor, try tightening the muscles that stop the stream of urine. Some people practice this by stopping and starting again when using the bathroom. Gradually build up to holding the position for 10 seconds or longer, and repeat it throughout the day.
Some people may need to meet with a physical therapist, who can give them tips and advice on how to improve and fully enjoy sex.
There is no “right” way to feel about sex and no correct way to have sex. People can experience sexual pleasure from a wide range of positions, types of sex, and sexual fantasies.
Open communication, self-acceptance, and a willingness to seek help when something does not work can promote sexual pleasure and reduce stigma.