The Facts About Sex

To fully understand sex—and to get the most out of it—it’s important to learn things like how orgasms work, the different kinds of sex and their risks, and more.

Understanding the orgasm

For both men and women, orgasm consists of four stages whose names vary from source to source but whose characteristics are similar: 1) excitement/desire/libido, 2) arousal/plateau, 3) orgasm/climax, and 4) resolution.

Excitement

This refers to a state of arousal, or the feeling of being “turned on.”

When women experience sexual excitement, there is an increased blood flow to the sex organs: the vagina, the clitoris and the nipples. Sexual excitement also causes a general flushed feeling all over the body as overall body temperature increases slightly and the heart rate increases.

When a man experiences sexual excitement, the brain sends a signal down the spine that triggers increased blood flow to the shaft of the penis, and that produces an erection. Veins in the penis that typically circulate blood in and out of the organ clamp themselves shut, allowing the erection to be maintained.

Sexual excitement, for both men and women, causes increases in blood pressure and heart rate, which then increases the brain’s production of serotonin and dopamine, the hormones associated with feelings of pleasure.

Plateau

After the initial sexual excitement, there is the plateau. It is during this period of sexual activity when sexual tension gradually increases, causing increased blood flow, heart rate and muscle tension, as well as faster breathing.

During the plateau stage, men will often experience the excretion of pre-ejaculatory fluid from the urethra. This fluid has a purpose. It changes the pH level in the urethra, which helps enhance the chances that the sperm will be able to survive when it leaves the body.

Climax

When a woman reaches her climax—or orgasm—the vagina and pelvic muscles will contract. A release of sexual tension takes place, and a sensation of warmth starts in the vagina and works its way throughout the entire body.

Men have two phases of orgasm: emission and ejaculation. During the climax, semen starts to move at the top of the urethra and is then released through contractions of the muscles in the penis, as well as muscles located near the anus. Once ejaculation starts, the nerves that cause those contractions send pleasure messages to the brain.

Resolution

After orgasm has been reached, the body transitions into a period of resolution where increased blood flow to the sexual organs subsides and the body relaxes.

Types of sex: risks and benefits

Sex comes in more than one variation. The several different types include oral, anal and vaginal sex. Each type comes with its own risk and benefits.

Oral sex

Oral sex refers to the act of using your mouth to stimulate your partner’s genital area or anus.

It is highly unlikely that a woman could get pregnant from oral sex, and the chances of catching a sexually transmitted infection (STI) during oral sex are also low, though it certainly can happen. Condoms and dental dams are recommended in order to reduce these risks significantly.

Evidence exists that oral sex may contribute to throat cancer. When the human papillomavirus (HPV) is passed from one person to another, that can increase the risk.

Anal sex

Anal sex can be an extremely pleasurable pastime between consenting adults, but there are some things you should keep in mind before starting. While anal sex cannot cause a pregnancy, it can increase the chances of catching an STI if a condom is not used.

Lubrication is important when it comes to anal sex. Without it, small rectal tears can occur and increase the chances of bacterial infection, and cause overall pain and discomfort. When using a condom, it’s important not to use oils such as baby oil or petroleum jelly–based products like Vaseline. Oil-based lubricant can weaken or break a condom, but there are plenty of silicone- and water-based lubricants that are safe and effective.

Vaginal sex

Vaginal sex can be fun and exciting between consenting adults. It’s important, though, to be aware that having unprotected vaginal sex not only increases the chances of getting or spreading an STI, but also the risk of unwanted pregnancy.

Have safer sex

For many people, sex is a big part of everyday life. While it can be both exciting and satisfying, it’s important to practice sexual health for the sake of you and your partner. Using protection is essential to prevent the spread of STIs and to avoid an unwelcome pregnancy. If you are in a non-committed relationship and prefer to have sex without a condom, it’s essential that you and your partner get checked regularly for STIs.