Genderfluid

Genderfluid aka Gender-fluid, Gender Fluid, or Fluid Gender, is an identity under the multigender, nonbinary, and transgender umbrellas. Genderfluid individuals have different gender identities at different times. A genderfluid individual's gender identity could be multiple genders at once and then switch to none at all, or move between single gender identities, or some other combination therein. For some genderfluid people, these changes happen as often as several times a day and for others, monthly, or less often. Some genderfluid people regularly move between only a few specific genders, perhaps as few as two (which could also fit under the label bigender), whereas other genderfluid people never know what they'll feel like next.

To be easy to read, this article uses the word "genderfluid" for all people who experience fluid gender. Some people who experience fluid gender don't use the word "genderfluid" for themselves. Some people with fluid genders use other labels such as genderqueer, bigender, multigender, or polygender. It's important to understand that each person has the right to decide what to call their gender identity.

History
The word "genderfluid" has been in use since at least the 1990s. In the 1990s and 2000s, it might have been more common for genderfluid people to call themselves bigender or genderqueer. Earlier than that, they may have called themselves cross-dressers.

The earliest extant entry for "gender fluid" in the Urban Dictionary was added in 2007.

In 2010, the Gender-Fluid community was created on LiveJournal.

In 2014, "Gender Fluid" was one of the 56 genders made available on Facebook.

In 2015, Dictionary.com added an entry for "gender-fluid,"  which it defined as an adjective meaning "noting or relating to a person whose gender identity or gender expression is not fixed and shifts over time or depending on the situation." It listed as synonyms genderfluid, gender fluid, and gender-flexible.

Influences on gender fluidity
Usually, gender fluidity happens by itself, so that a person feels like, say, a girl at a certain time, rather than choosing to be a girl at a certain time. Some genderfluid people find that no outside or inside things tend to influence their gender identity to change. They find that their gender fluidity is unpredictable and happens randomly. Other genderfluid people find that their gender changes depending on the situation and is influenced by inside or outside sources. Some move from one gender to the next on a regular cycle, resembling a lunar cycle, or synchronizing with their menstrual cycle. Other genderfluid people are sometimes able to use their willpower to guide their gender to change in a way and/or at the time that they want it to.

Menstrual cycle and its effect on gender fluidity
While it is still unclear, changes in gender that correlate with the menstrual cycle could be caused by how hormone levels naturally rise and fall during menstruation. However, it's also possible to mistakenly believe that gender identity moves with the menstrual cycle, and the only way to be sure is to keep a daily journal. Such a journal could look like this: After enough data is collected, any patterns that exist should become visible. These patterns could include feeling like a certain gender during a certain day in the cycle or feeling like a certain gender at times when a certain hormone, such as estrogen, is highest/lowest. Similar tables can be used to track if gender identity is connected to a different cycle.

In 2012, Case and Ramachandran gave a report on the results of a survey of genderfluid people who call themselves bigender who experience involuntary alternation between female and male states. Case and Ramachandran gave this condition the name "Alternating gender incongruity (AGI)." Case and Ramachandran made the hypothesis that gender alternation may reflect an unusual degree (or depth) of hemispheric switching and the corresponding suppression of sex appropriate body maps in the parietal cortex. They "hypothesize[d] that tracking the nasal cycle, rate of binocular rivalry, and other markers of hemispheric switching will reveal a physiological basis for AGI individuals' subjective reports of gender switches... We base our hypotheses on ancient and modern associations between the left and right hemispheres and the male and female genders." Case and Ramachandran believe that when bigender people feel a change between their gender identities, it may have to do with a change in how they use parts of their brains. The gender change might also have to do with a natural body cycle, specifically, a valve in the nose that changes sides every two days (the nasal cycle). However, this idea is still only a hypothesis, and more study is needed to confirm it.

Gender expression
Genderfluid people often feel a need to change their gender expression to match whatever their current gender has become. This may mean having groups of different kinds of clothing in their closet, so they can dress as a woman, man, or otherwise, depending on how they feel that day. It can also mean temporarily changing their body shape by using binding, packing, breast prostheses, or tucking. However, in some situations, changing gender expression isn't possible. This could be because the changes happen more than once a day, because they don't look androgynous, or because they don't feel safe in society if they were to present a certain way.

Genderfluid people don't necessarily look androgynous. They don't necessarily have an ambiguous face, body, or way of dress.

Gender dysphoria, or feeling painfully uncomfortable about how one's body and social role don't match one's gender, isn't a requirement in order to be genderfluid. Each person is different, experiencing gender fluidity in their own way. Some genderfluid people experience gender dysphoria at times or all the time. Some want to change their bodies and some take a physical transition to do so, which may include hormones or surgery. Others don't choose to transition because any change they make to their body would only feel right to them when they were in a certain gender and would feel wrong in others. Yet others have a difficult time planning their transition path, because their feelings change about what they want.

Some genderfluid people ask to be called by a different name  and pronouns depending on what gender they feel at a certain time. For people who switch between only two genders, this can mean switching between two names. These may be feminine and masculine versions of the same name  or names that don't sound similar at all. They may also take a gender-neutral name that works for them at any time, either in addition to these names, or instead of them.

Gender fluidity and dissociative identity disorder
Genderfluid people usually don't think of themselves as having alters. Most genderfluid people feel like the same person all the time, with the same likes and dislikes but a different gender. However, some genderfluid people switch between specific personas as they change genders, and each persona has their own likes and dislikes. This is different from Dissociative Identity Disorder (DID), which is a disorder characterized by dissociation and the existence of alters. DID is caused by traumatic abuse that happens early in childhood and almost always exists alongside PTSD or cPTSD. Gender fluidity is not caused by abuse and is not more common in people with PTSD or cPTSD.