The best known of these surgeries are those that reshape the genitals, which are also known as genital reassignment surgery or genital reconstruction surgery (GRS).
The meaning of sex reassignment surgery usually differs for transwomen (male to female) rather than transmen (female to male). For transwomen, sex reassignment usually involves the surgical construction of a vagina, whereas in the case of transmen, this term may entail any of a variety of procedures, from the mastectomy (removal of the female breasts) to the shaping of a male-contoured chest to the construction of a penis. Additionally, transmen usually undergo a hysterectomy and bilateral salpingo-oophorectomy.
Chest (or "top") surgery is often the only surgical procedure female-to-male transsexuals choose to undergo, as GRS techniques for transmen are still rather unrefined and typically produce genitalia of compromised aesthetic and functional quality.
People who pursue sex reassignment surgery are usually referred to as transsexual; "trans" - across, through, change; "sexual" - pertaining to the sexual characteristics (not sexual actions) of a person. More recently, people pursuing SRS often identify as transgender instead of transsexual.
Many use the terms sex reassignment therapy, "sex reassignment” or "sex reassignment surgery" (aka SRS) to describe these medical procedures. However, many in the transgender community find these terms offensive. Implicit in the word "reassignment" is the idea that someone other than the self can "assign" or otherwise decide a person's gender. This is in clear conflict with the concept of "gender identity" which is a person's internal knowledge of their own gender. Many transgender and transsexual individuals feel strongly that their internal sense of their gender - their gender identity- is not subject to the assignment or reassignment by others. While some feel that the term "sex reassignment surgery" would more accurately be called "genital reassignment surgery" or "genital reconstruction surgery", it is important to note that the surgeries related to transgender transition go beyond the genitalia, and that the medical procedures go beyond surgery.
Other health conditions such as diabetes, abnormal blood clotting, and obesity do not usually present a problem to experienced surgeons, but do increase the anesthetic risk and the rate of post-operative complications. Some surgeons require that severely overweight patients reduce their weight by a certain amount prior to surgery and that patients refrain from smoking for a period of time before and after surgery, although this is considered common practice regardless of the operation performed.
Additionally, it is usually necessary for transsexual people to continue hormone replacement therapy in order to maintain their secondary sex characteristics and prevent conditions such as osteoporosis.
Transsexual people who do not undergo SRS/GRS are often called non-op, while "gender refusenik" is a slang term used among transgender people. Possible reasons for forgoing SRS include financial, legal, and medical concerns, among others.
In many countries or areas, an individual's pursuit of SRS is often governed, or at least guided, by documents called Standards of Care for Gender Identity Disorders (SOC). This most widespread SOC in this field is published and frequently revised by the World Professional Association for Transgender Health (WPATH, formerly the Harry Benjamin International Gender Dysphoria Association or HBIGDA). Standards of Care usually give certain very specific "minimum" requirements as prerequisites to SRS. For this and many other reasons, both the WPATH-SOC and other SOCs are highly controversial and often maligned documents among transgender patients seeking surgery. Some alternative local standards of care exist, such as in the Netherlands, Germany, and Italy. Much of the criticism surrounding the HBIGDA-SOC applies to these as well, and some of these SOCs (mostly European SOC) are actually based on much older versions of the WPATH-SOC. Other SOCs are entirely independent of the WPATH. The criteria of many of those SOCs are stricter than the latest revision of the WPATH-SOC. The majority of qualified surgeons in North America and many in Europe adhere almost unswervingly to the WPATH-SOC or other SOCs.
The earliest identifiable recipient of Male to Female Sex Reassignment Surgery was Lili Elbe in Berlin, in 1930-1931. This was started with the removal of the male sex organs and was supervised by Dr. Magnus Hirschfeld. Lili went on to have four more subsequent operations that included an unsuccessful uterine transplant, the rejection of which resulted in death. An earlier known recipient of this was Magnus Hirschfeld's housekeeper, but her identity is unclear at this time.