In his book, Benjamin described "true" transsexualism as the following:

True transsexuals feel that they belong to the other sex, they want to be and function as members of the opposite sex, not only to appear as such. For them, their sex organs, the primary (testes) as well as the secondary (penis and others) are disgusting deformities that must be changed by the surgeons knife. Relationship to transgender
The term transgender was coined by John Oliven in 1965. By the 1990s, transsexual had come to be considered a subset of the umbrella term transgender. The term transgender is now more common, and many transgender people prefer the designation transgender and reject transsexual. Some people who pursue medical assistance (for example, sex reassignment surgery) to change their sexual characteristics to match their gender identity prefer the designation transsexual and reject transgender. One perspective offered by transsexual people who reject a transgender label for that of transsexed is that, for people who have gone through sexual reassignment surgery, their anatomical sex has been altered, whilst their gender remains constant.Historically, one reason some people preferred transsexual to transgender is that the medical community in the 1950s through the 1980s encouraged a distinction between the terms that would only allow the former access to medical treatment.
Some people posit that transsexualism is a physical condition, not a psychological issue, and assert that sex reassignment therapy should be given on request. (Brown 103)
Like other trans people, transsexual people may refer to themselves as trans men or trans women. Transsexual people desire to establish a permanent gender role as a member of the gender with which they identify, and many transsexual people pursue medical interventions as part of the process of expressing their gender. The entire process of switching from one physical sex and social gender presentation to another is often referred to as transitioning, and usually takes several years. Transsexual people who transition usually change their social gender roles, legal names and legal sex designation.Not all transsexual people undergo a physical transition. Some have obstacles or concerns preventing them from doing so, such as the expense of surgery, the risk of medical complications, or medical conditions which make the use of hormones or surgery dangerous. Others may not identify strongly with another binary gender role. Still others may find balance at a midpoint during the process, regardless of whether or not they are binary-identified. Many transsexual people, including binary-identified transsexual people, do not undergo genital surgery, because they are comfortable with their own genitals, or because they are concerned about nerve damage and the potential loss of sexual pleasure, including orgasm.