What Does It Mean to Be Intersex?

Medically Reviewed by Zilpah Sheikh, MD on March 31, 2024
8 min read

Intersex is an umbrella term for people who are born with one or more traits in their chromosomes, genitals, hormones, or internal reproductive organs that don’t fit the typical male or female patterns. Some of their traits might not match the sex they were assigned at birth or may combine traditionally understood male and female traits. 

While intersex traits are often noticed at birth, the differences aren't always obvious then. People might discover they have intersex traits at puberty or in adulthood, sometimes as a result of medical testing for infertility. In rare instances, such differences are found in autopsies, after people have died. 

It's important to note that intersex people may use varying terms to describe their differences. While many reject the language used by some medical organizations – "disorders of sex development" – some use the term "differences of sex development." The most widely used description is intersex.

Sex vs. Gender

To understand intersex differences, it helps to consider that sex and gender are not the same.

Sex is almost always defined as either female or male by the health care providers who help people give birth. It's what goes on birth certificates. The decision is most often based on the appearance of your genitals – whether it looks like you have a penis or a vagina. If testing is done, sex may also be defined by hormone levels, chromosomes, and reproductive anatomy, like having ovaries or testicles. 

Gender is a more complex concept. Used at a cultural level, it means the behavior, appearance, and roles society expects of people, based on their assigned sexes. Those can differ from one culture and one time to another. Used individually, it can refer to your own perceptions and identity, regardless of your assigned sex at birth or the social perception of your gender. 

Intersex people can have varying gender identities, like anyone else. Most have a gender identity that matches the sex they were assigned at birth. Being intersex isn't the same as being transgender. But if someone with intersex traits identifies with a gender different from their sex assigned at birth, they might consider themselves transgender. Or they might identify as nonbinary – meaning neither male or female – or other genders.

Being intersex also has nothing to do with sexual orientation, meaning who you are attracted to. An intersex person could be straight, gay, bisexual, asexual (not interested in sex), or have some other sexual orientation.

Intersex chromosomes

Most people are born with 46 chromosomes, containing their genetic information, in each of their cells. These chromosomes come in 23 pairs, and one of those pairs, called the sex chromosomes, helps determine whether someone develops typical male or female physical traits. Most males have one X and one Y chromosome. Most females have two X chromosomes.

But sometimes, a child is born with different chromosome arrangements that affect sexual development. For example, they might have just one X chromosome or a combination like XXY. Or some of their cells might have different sex chromosomes than others do. For example, some cells might have XY chromosomes and some might have XX. That kind of cell-to-cell genetic difference is called mosaicism.

It's also possible for intersex people to have sex chromosomes typical of males or females, but to have body traits that aren't typical for that sex.

Intersex anatomy

When someone is intersex, they might have body differences a doctor could notice at birth or internal differences that could go unnoticed. For example, a baby might have a larger than usual clitoris, no vaginal opening, a very small penis, or other features that doctors sometimes refer to as ambiguous genitalia, meaning features that make determining sex more difficult. An intersex person might have both ovarian and testicular tissue. 

Most people are assigned a gender at birth, boy or girl, based on whether medical providers see typical male anatomy, a penis and testicles, or female anatomy, a vagina and vulva. If they see unusual features, they might test hormones and genes and do some imaging tests to see inner reproductive organs. At that point, even if the person has intersex traits, they are labeled a boy or girl, based on what doctors know about how similar people usually develop.

In the past, it was common for babies and young children to get surgery for traits that didn't match their assigned gender, but that practice is being discouraged more. One major reason is that people may decide later that they were given the wrong gender and they want sexual organs different from those that their parents and doctors chose.


It's estimated that 1% to 2% of the population has intersex traits. That makes it more common than having red hair or being an identical twin.

Some things that may cause intersex traits include: 

  • Genetic conditions that affect hormone levels during development 
  • Other hormone exposures, from drugs or other sources, during early development
  • Random chromosome variations that happen at conception

In many cases, no specific cause is found.

Being intersex isn't a disorder or a disease. Intersex traits can show up in about 40 ways, so there's no description that fits everyone involved. There's no single way an intersex person looks and no single way intersex traits affect them.

For example, you might have:

  • A penis, but levels of estrogen more typical of females than males
  •  No penis, but otherwise typical male traits
  •  Sex glands that contain both ovarian and testicular tissue (ovotestes)
  •  Ovaries and a uterus, but no vagina
  • A vagina, along with undescended testicles, no menstrual periods, and infertility as a result of a gene difference (androgen insensitivity syndrome) 

While intersex variations aren't disorders, they sometimes are part of other conditions that can cause health problems. For example, some babies born with a large clitoris have a condition called congenital adrenal hyperplasia that affects how the body makes and responds to stress hormones. Some variations in testicles or ovaries are linked with an increased cancer risk. Intersex people who have their testicles or ovaries removed can develop other problems, including fragile bones, especially if they don't get adequate hormone replacement therapy. 

How to tell if you're intersex

In many cases, it's clear from the outward appearance of your body. Or you may know, based on your medical history, that you don't have typical ovaries or testicles or have a sex chromosome difference.

Sometimes, the first clue comes when someone doesn't go through puberty as expected – for example, when someone assigned female at birth doesn't get periods or someone assigned male grows breasts. Or you might be infertile – meaning you are not able to get pregnant or get someone else pregnant when you want to. These conditions have many other causes, though.

 Some people who've never been told about their medical histories may remember multiple genital surgeries during childhood or have unexplained scars around their genitals and bellies. In general, if your genitals look pretty much the same as those of other men, women, boys, or girls, those are probably the genitals you were born with. Even today, surgery doesn't produce completely typical genitals. Techniques in the past were less advanced.

Intersex people typically don't need surgery, though some may choose it. Advocates for intersex people say unneeded surgeries on infants and children who can't consent to them have caused serious physical and psychological harms and should not be done today. The United Nations and some medical groups have taken similar positions. Some states are looking at policies that would limit or outlaw the practices.

In the past, these surgeries were often done on children under age 2 and were aimed mostly at making their genitals and reproductive organs match their sex assigned at birth. Advocates today urge parents to avoid any medically unnecessary surgery and let their children make their own choices when they are old enough.

In limited cases, surgery might be needed, even on a baby – such as one who can't pee because they were born with no urinary opening. 

When people do choose surgery, it can take many forms. For example:

  • Clitoroplasty, or clitoral reduction, to reduce or move the clitoris
  • Vaginoplasty to create a vagina or change its appearance 
  • Hypospadias repair to move the urethra (the opening for pee) when it's not at the tip of the penis 
  • Gonadectomy to remove testicles or ovaries and change hormone levels 

Intersex surgery risks and complications 

Intersex physical traits themselves usually carry no medical risks. Surgery can come with risks including:

  • Problems with sexual functioning, including reduced sensation
  • Infertility
  • Scarring
  • Urinary tract infections 
  • Urine leaks

Unwanted medical exams, hormone treatments, and surgeries can all be traumatic for a child. Surgery can add to future psychological distress, especially if the person later identifies as a gender different from their assigned sex. 

Many people who have intersex traits or have intersex children wonder about reproduction and pregnancy rates. There's no simple answer. Whether an intersex person can get pregnant or get someone else pregnant depends upon the person’s body parts, hormones and other things – including, sometimes, access to fertility treatments. 

For example, if an intersex person has a penis and sperm-producing testicles, they may be able to cause pregnancy. Likewise, if an intersex person has a uterus, they may be able to get pregnant.

The use of in-vitro fertilization; donated eggs, sperm, and embryos; and surrogates who can carry a pregnancy may provide options for some people.

While many intersex differences may result in infertility, not all do. Parents should know that surgery to change intersex traits can sometimes cause infertility. 

Intersex traits aren't as rare as once thought, and intersex people can find others to talk to, online and in person. There are intersex groups on Facebook and elsewhere on the internet and conferences where intersex advocates gather to share experiences and work toward changes in society.

Some groups welcome parents or other allies. Some are for people with particular medical conditions that come with with intersex traits.

Parents can support intersex children by being open and honest about their bodies and any differences. Not talking about these things can lead children to feel ashamed of their bodies. Parents also can help by finding understanding medical providers who won't pressure the family into unneeded surgeries or other treatments, advocates say.

If you know someone who's intersex, let them share as much of their story as they want. Don't ask personal questions about their genitals or medical history. If they do share personal details, ask if it's OK to share any of that information with others. Follow their lead when it comes to their gender identity – whether they consider themselves male, female or otherwise – and whether they use the term intersex to refer to their differences.


Intersex traits are part of the human condition. They can show up in a variety of ways, and most aren't linked to any health problems. Advocates stress that unneeded surgery to change the genitals or other traits of children before they can consent has caused physical and psychological harm to many people.