There are two main contexts where someone who looks like or identifies as a girl or woman may have a penis. The first is a group of biological conditions collectively called differences in sex development (also known as intersex traits). The second is being transgender, where a person’s gender identity as female differs from the male sex they were assigned at birth. Both have specific terminology, and the answer depends on whether you’re asking about biology, identity, or both.
Differences in Sex Development (Intersex Traits)
Sometimes a baby is born with a body that doesn’t fit neatly into the typical definitions of male or female. The medical umbrella term for this is differences in sex development, or DSD. Some people and advocacy groups prefer the word intersex. These are rare but real biological variations involving genes, hormones, and reproductive organs that cause a person’s physical sex characteristics to develop differently than expected. Experts estimate that up to 1.7% of the population is born with some form of intersex trait, though many of these are subtle and may go unnoticed.
Several specific conditions can result in a person who appears female having genitalia that look partly or fully male.
Congenital Adrenal Hyperplasia (CAH)
CAH is one of the most common causes. In this condition, the adrenal glands lack an enzyme needed to produce certain hormones, especially cortisol. To compensate, the glands overproduce androgens (hormones that drive male-typical development). In a baby with XX chromosomes (the typical female pattern), this flood of androgens during pregnancy can cause the external genitalia to develop in a way that resembles typical male anatomy. The baby still has typical internal female organs, including ovaries and a uterus, but the outer appearance can range from a slightly enlarged clitoris to genitalia that look very similar to a penis and scrotum. Doctors classify this as 46,XX DSD.
Androgen Insensitivity Syndrome (AIS)
AIS works in the opposite direction. A person with XY chromosomes (the typical male pattern) has cells that can’t respond to testosterone properly due to a gene variation. In complete androgen insensitivity, the body ignores androgens entirely, so the person develops external genitalia that look typically female and is usually raised as a girl. They have internal testes rather than ovaries, and typically no uterus, but outwardly their body appears female. In partial androgen insensitivity, the result is somewhere in between: genitalia may have features of both sexes, or may look mostly male or mostly female.
5-Alpha Reductase Deficiency
This is the condition behind the phenomenon sometimes called “güevedoces” in the Dominican Republic, where children raised as girls develop male genitalia at puberty. People with this condition have XY chromosomes but lack enough of an enzyme that converts testosterone into a more potent form needed for typical male genital development before birth. Many are born with external genitalia that appear female. Then, during puberty, rising testosterone levels trigger the growth of the penis and scrotum, deepening of the voice, increased muscle mass, and other male-typical changes. The body essentially completes a delayed phase of male development.
Ovotesticular DSD
In very rare cases, a person is born with both ovarian and testicular tissue. This condition, called 46,XX ovotesticular DSD, can result in genitalia that have characteristics of both sexes. The external appearance varies widely from person to person.
How Intersex Conditions Are Identified
In newborns, genital anatomy that doesn’t clearly match male or female patterns is sometimes called ambiguous genitalia. One specific measurement doctors use involves clitoral length at birth: under 5 millimeters is considered typical for a female newborn, anything over 10 millimeters is considered a sign that something unusual is happening hormonally, and values between 8 and 10 millimeters are monitored closely.
When a baby’s genitalia don’t fit standard expectations, a team of specialists typically evaluates the child. This may include hormone testing, imaging to look for internal reproductive organs, and chromosome analysis. The goal is to understand the underlying biology so families can make informed decisions about gender assignment and, if needed, medical care.
The Debate Over Early Surgery
For decades, doctors in the United States performed surgery on intersex infants to make their genitalia look more typically male or female. The reasoning was that a “normalized” appearance would reduce stigma and help with parent-child bonding. That approach has shifted significantly. A major international consensus statement published in 2006 found no scientific basis for the idea that early cosmetic surgery improves bonding, and recommended that surgery on an enlarged clitoris should only happen in cases of severe virilization, with priority given to preserving sensation and function rather than appearance.
Intersex advocacy organizations go further, arguing that cosmetic genital surgery should wait until the person is old enough to participate in the decision with full informed consent. Their position is straightforward: surgery removes tissue the person may want later, causes irreversible changes, and denies a child agency over their own body. Current medical guidelines increasingly reflect this perspective, emphasizing mental health support, full disclosure to patients and families, and caution around irreversible procedures.
Transgender Women
The other common context for this question involves transgender women. A transgender woman is someone who was assigned male at birth based on her physical anatomy but whose gender identity is female. The clinical term “transgender” simply describes this mismatch between assigned sex and gender identity. Some transgender women pursue hormone therapy or surgery to align their bodies with their identity, and some do not. A transgender woman who has not had genital surgery retains male-typical genitalia while living and identifying as a woman.
The older clinical term “transsexual” was historically used specifically for people who sought medical interventions like hormones or surgery. That term has largely fallen out of common use, though some individuals still identify with it. More current language includes “trans woman” or “trans-feminine,” with the latter sometimes used as a broader term for people on the feminine end of the gender spectrum who were assigned male at birth.
Why the Language Matters
The terminology around these topics has changed a lot over the past few decades, and for practical reasons. Older medical terms were often stigmatizing or inaccurate. “Hermaphrodite,” for example, was once used clinically for intersex people but is now considered outdated and offensive by most medical organizations. “Disorders of sex development” is still used in some clinical settings, but many people prefer “differences in sex development” or “variations in sex characteristics” because these terms describe biology without implying something is broken.
For transgender individuals, language has similarly evolved. The key distinction most organizations and clinicians now draw is between sex (the physical body you’re born with) and gender identity (your internal sense of being male, female, or something else). Using terms that respect this distinction isn’t just about politeness. It reflects a more accurate understanding of how human biology and identity actually work, where chromosomes, hormones, anatomy, and self-perception don’t always line up in the way most people assume.