HowStuffWorks explores the functions -- and dysfunctions -- of the reproductive system. Learn about maintaining a healthy sex life and avoiding and treating sexual problems.
In high school biology, we're taught that biological sex is a game of X and Y. In recent decades, though, scientists have learned that things might not be so clear-cut. That may seem unusual to us, but it wouldn't surprise a clownfish one bit.
You only have to get your heart broken once to wonder why the opposite sex exists. Why must men be from Mars and women from Venus? Why must we live in a world divided by pink and blue? Wouldn't things be a lot easier if we were all one biological sex?
There are all sorts of old wives' tales about how to influence the biological sex of your unborn baby. Eat red meat for a boy, chocolate for a girl. But while science is starting to give parents the chance to pick sex, there's no sure way to pick a baby's gender. Wait -- they're not the same thing?
What are the definitions of Masters and Johnson terms? Learn about research and studies by sex therapists Masters and Johnson.
What are the causes and treatments of sexual pain disorder? Learn about the causes and treatments of sexual pain disorder.
What are the definitions of erotica terms? Learn about how erotica can stimulate or enhance sexual arousal and performance.
If you're like most men, you'd rather ignore the pain than go to the doctor and talk about pain "down there." But in many cases, trying to pretend the pain away could mean worsening your problem -- even to the point of needing your testicles removed.
When it comes to sex, what is normal, exactly? For most issues, "normal" spans a pretty broad range. But life with these unusual sexual conditions definitely isn't typical.
A common complaint for many women is the loss of libido, or sex drive. While no one resolution exists, certain strategies can offer significant help for this condition and overall well-being. Learn about the causes and treatment of low libido.
Testosterone and estrogen are actually very closely related in the body, and maintaining the balance of these hormones is key to preventing health issues. Learn about proper testosterone and estrogen balance in men.
When is sex hot and when is it not? Read other people's opinions of when sex is hot and when it's not to see how different people's preferences can be.
What is the definition of an aphrodisiac? Learn how aphrodisiacs can initiate or intensify sexual arousal.
What is the definition of asexual behavior? Learn about asexual behavior in humans and other organisms.
What is the definition of circumcision? Learn about the origins, risks and benefits of circumcision.
What is the definition of clitoris? Learn about female sexual anatomy and the functions of the clitoris.
What is the definition of cunnilingus? Learn about how cunnilingus, a form of oral sex, is performed.
What is the definition of ejaculation? Learn about what's happening during ejaculation and its purpose in reproduction.
What is the definition of an erection? Learn what's happening during an erection and how dysfunction occurs.
What is the definition of fellatio? Learn how fellatio, a form of oral sex, is performed.
What is the definition of fetishism? Learn about how fetishism affects a person's sexual behavior.
What are the definitions of foreplay terms? Learn about different types of foreplay activities that precede sexual intercourse.
What is the definition of dyspareunia? Learn about how painful sex, also known as dyspareunia, can affect a person's sexual health.
What is the definition of gay? Learn how the term gay has come to indicate homosexuality.
What are the definitions of genitals and genitalia terms? Learn about the anatomy and physiology of genitals and genitalia in both males and females.
What are the definitions of gynecology terms? Learn about how the medical field of gynecology provides health care to women.