Sex describes your biology (male or female chromosomal makeup, hormones, and/or anatomy)Gender describes how you understand yourself as a man (masculine), a woman (feminine), a mixture of the two, or something else entirely

That’s a good start toward understanding gender vs. sex, but there’s far more to it. The categories “male and female,” “masculine and feminine,” and “man and woman” do not capture every person.

For example, someone’s sex may be male while their gender is feminine. Or their sex may be female while their gender isn’t masculine or feminine. Both sex and gender exist on their own spectrum, and the two spectrums don’t always interact in the same way.

This article delves into the different aspects of sex and gender, the terminology that’s developed to describe it, how gender relates to sexual orientation, the kinds of medical care available to people who fall outside of the gender binary, and how you can be a good ally.

Understanding Biological Sex

The biology of sex starts with a discussion of chromosomes, hormones, and anatomy.

The Role of Sex Chromosomes

The two types of sex chromosomes are X and Y.

Most people have two sex chromosomes. Those with two X chromosomes (XX) are usually female. Those with an X and a Y (XY) are usually male.

Having two distinct, opposite sexes (male and female) is called binary. Another term for it, which means all of someone’s sex characteristics belong to one biological sex, is endosex.

Chromosomal Variations

However, researchers have learned that biological sex isn’t always that simple. Some people:

Have one sex chromosome (X) Have three sex chromosomes, called trisomy (XXX, XXY, XYY)

Sometimes, these variations lead to a combination of male and female biological traits (for example, ovaries and testicles), which is called being intersex. Other times, though, it results in someone who’s endosex.

In addition, some people have:

Two sex chromosomes (XX, XY)But dysfunctional genes on one of the chromosomes

That can lead to someone being, for example, an XY woman or someone who’s non-binary. Some of these combinations cause medical problems which are called differences in or disorders of sexual differentiation.

Other combinations don’t cause medical problems and simply represent normal genetic differences.

The Role of Sex Hormones

The next major aspect of biology that determines sex is hormones and hormone receptors.

Everyone has the hormones that are associated with sex characteristics, but males have more male hormones (like testosterone) and females have more female hormones (estrogens).

Exposure to sex hormones helps guide a fetus’s development of sex characteristics.

Exposure to Sex Hormones

A fetus develops structures associated with the male sex, such as a penis, when it’s exposed to testosterone. This testosterone comes from their own developing testes.

When a fetus isn’t exposed to testosterone, it develops structures associated with the female sex, such as a vagina and uterus.

In some cases, a fetus with XY chromosomes is exposed to amounts of testosterone that are too small to cause male structures to develop. That can lead to an intersex baby.

If the pregnant person has high levels of testosterone (due to illness or hormone therapy), it’s possible for them to pass some of it along to a fetus. Researchers have yet to fully understand the effects of this.

However, so far, it appears that these elevated testosterone levels can lead to females with:

More aggressive play behaviorsA sexual orientation other than heterosexual (“straight”)A gender identity that doesn’t match the biological sex they were assigned at birth (trans)

The Role of Anatomy

Your anatomy is your bodily structure. That includes your genitalia. The sex noted on your birth certificate is a reflection of what genitalia healthcare providers saw when you were born.

In some intersex cases, the assigned sex may be based on a best guess, since forms haven’t historically included anything beyond the male-female binary.

While the anatomical appearance of genitalia often reflects the chromosomal and hormonal makeup of the child, it doesn’t always.

Understanding Gender and Gender Identity

Gender describes social and cultural attributes associated with masculinity and femininity. It’s separate from biological sex.

Your gender identity is your personal understanding of yourself as masculine, feminine, a combination thereof, or something else entirely. Awareness of gender diversity in humans has grown along with the increasing visibility of transgender people.

If your gender identity is typical of the sex on your birth certificate, you’re called cisgender. If your gender identity is not typical of the sex on your birth certificate, possible terms may include:

Transgender/trans: Someone who is not cisgender. Often used as an umbrella term for all of the below. Trans male/trans female: The “male” or “female” refers to the person’s gender identity; for example, a trans male is someone assigned female at birth who identifies as male. Gender nonconforming: An umbrella term for non-cis people who don’t follow gender stereotypes or have an expanded idea of gender identity and expression. Genderfluid/queergender/bigender: An identity that encompasses or fluctuates between two genders (often male and female but not always). Agender: Someone who doesn’t identify with any gender. Nonbinary: Someone who doesn’t subscribe to the gender binary; may be somewhere between masculine and feminine; sometimes used interchangeably with genderqueer or other terms.

Some of these terms overlap or may seem redundant. Even if you don’t understand the nuances, it’s important to use the right terms. So, if someone tells you they’re genderfluid, don’t call them queergender or nonbinary.

People who fall into any of these categories may choose to use transgender or trans, as well. Not all of them do.

Pronouns

Once someone has made their gender identity known, you should use their preferred pronouns. A pronoun is a word used in place of a name or names.

Assigned male at birth (AMAB)Assigned female at birth (AFAB)

Common pronouns include:

I/me/my/mineHe/him/hisShe/her/hersThey/them/their/theirsWe/us/our/oursYou/your/yoursIt/its

Many trans people use the pronouns that go along with their gender identity, not the sex they were assigned at birth (example: a trans woman who’s called she or her).

Some choose to use gender-neutral pronouns: they/them/their/theirs. Because these are also used as plural pronouns (denoting more than one person), this can be awkward or confusing. It is considered grammatically correct, though, along with being courteous.

Some people prefer newer pronouns that are considered gender neutral, such as “hir” or “zie” instead of him or her.

Changing the pronouns you use for someone can be hard. However, it’s important to try, as it can be psychologically damaging to a trans person to misgender them with pronouns.

It is never appropriate to use “it” for a person, regardless of their gender identity. Mashed-up terms like “he-she” or “shemale” are highly offensive.

What Is Gender Expression?

In addition to gender identity, people also have gender expression. That describes the gendered ways you present yourself to the world.

Your gender expression may or may not reflect your gender identity. For example:

A cisgender woman with short hair who likes to wear tailored suits is still a woman, though some people may see her presentation as masculine. A transgender man who wears makeup is still a man despite presenting in a way that’s generally considered feminine.

Someone can be trans and still present themselves as the sex they were assigned at birth. Many circumstances may prevent someone from presenting in a way that matches their gender identity. This includes young people whose parents don’t allow them to express a certain way.

Regardless of gender presentation and expression, it’s appropriate to use the name and pronouns they’ve requested.

Gender Identity and Sexual Orientation

Gender identity is completely separate from sexual orientation. Like cis people, trans people can be:

StraightGay/lesbianBisexualPansexualAsexual

How someone describes their orientation generally relates to their gender identity, not their biology. For instance, a trans woman who’s attracted to men is considered straight. A trans man who’s attracted to men is considered gay.

Some research suggests that the orientation may sometimes shift during transition, such as after beginning hormone therapy. Someone who’s assigned female at birth may initially be attracted to men, then develop an attraction to women after going on testosterone.

However, this doesn’t happen to everyone and it may not affect ongoing relationships. Most trans people remain just as attracted to their partners after transition.

Gender-Affirming Care

Some people whose sex and gender don’t match choose to seek out gender-affirming medical treatment or surgical procedures.

Gender-affirming care includes a wide variety of interventions that help people align their social, emotional, and/or biological selves with their gender identity. It may include:

Counseling Changes in appearance Sex hormone therapy Gender confirmation surgery

Gender confirmation surgery used to be called sex reassignment surgery and, before that, a sex change operation. Those terms have fallen out of use.

Gender confirmation surgery alters someone’s appearance and sex characteristics to be more in line with their gender identity. Having breasts added or removed is often referred to as top surgery, whereas a change in genitalia is called bottom surgery.

The goal of gender-affirming care is to relieve gender dysphoria, which is the discomfort caused by a mismatch between someone’s body and their identity.

It’s considered inappropriate to ask a trans person whether they’ve had gender confirmation surgery or use hormones.

Not Everyone Transitions

Not everyone who’s trans makes a medical transition. Some of them may be waiting until they’re old enough, until they can afford it, or for some other milestone to be reached.

Others may never make medical changes to their bodies. This may be due to financial, social, or familial pressures. Or it may be that they don’t feel it’s necessary.

Trans people shouldn’t be judged for their choices regarding medical transition. No decision invalidates their assertions about their gender identity.

Intersex Care

Intersex people make up between 0.02% and 1.7% of the population, depending on the definition that’s used. Historically, doctors and parents have opted for early surgeries on intersex infants and young children to make them either male or female.

The goal was to “normalize” the appearance of the child’s genitalia. This was often done without the child’s input and/or before the child was old enough to be included in the decision.

The child was then generally raised as the gender that aligned with their genitalia. The belief was that having clearly male or female genitalia—and a gender expression that matched the genitalia—would lead to an easier and happier life.

However, that has often not been the case, and some of those children have eventually rejected the gender identity that was given to them.

Some parents and healthcare providers still choose genital surgery, hormones, and attempts to make an intersex child into male or female.

Beliefs are changing, though, and activists are calling for an end to these practices. They want the medical community to stop treating intersex as a medical problem and to allow the child to be part of the decision-making process when they’re old enough.

Respecting and Supporting Trans People

Even if you don’t understand someone’s gender identity, or trans identities in general, you can show them that you respect and support them. Ways to do this include:

Use the names and pronouns they ask for. If you make an occasional mistake, apologize, correct yourself, and move on. Try not to make assumptions about gender. Remember that identity and expression don’t always match. If you’re unsure what pronouns to use, ask. Advocate for trans-friendly policies, such as gender-neutral restrooms or rules stating they can use whichever they’re comfortable with, and choices on forms that go beyond the male-female binary. Accept that people are what they say they are. Don’t reject what they tell you based on their presentation, sexual orientation, or other traits. Don’t ask intrusive questions about their bodies, stage of transition, sexuality, or sexual practices. Recognize that someone’s idea of their gender may evolve over time. Identities and understandings of them can shift. Put your own preferred pronouns in places like your email signature or name tags—even if you’re cis—to normalize the practice.

Summary

Sex is biological and based on chromosomes, hormones, and anatomy. Gender is a set of social and cultural norms associated with masculinity and femininity.

Gender identity is your sense of whether you’re masculine, feminine, somewhere in between, or something else entirely. Gender expression is how you present yourself to the world.

People whose sex and gender “match” are called cisgender. Those who don’t have a match are transgender. Many terms exist that mean different things about the trans identity, including agender, genderfulid, and nonbinary.

Gender identity doesn’t dictate sexual orientation. Sometimes, hormone therapy during transition causes a shift in orientation.

Gender-affirming care helps people align their gender identities with their sex. It may include counseling, hormone therapy, or sex reassignment surgery.

Using the preferred name and pronouns for trans people shows that you respect and support them.

A Word From Verywell

If someone in your life is trans, it can be hard to make the changes they ask of you. Your willingness to work on those changes can go a long way toward showing them that you accept who they are and care about their happiness.

Having allies is important for trans people, no matter their age or stage in transition. Being an ally means putting some effort into educating yourself and working to overcome any prejudices you may have. It helps if you educate other people in your life about trans issues, as well.