Gender dysphoria is suite of mental symptoms experienced by transgendered patients who have been unable to feminize. It may be testosterone-driven.

Between driven & obstructed

The word dysphoria implies feeling badly.  Whereas "transsexuality" is an iconic label describing the drive experienced by patients who are concerned that their bodies are of the wrong gender, gender dysphoria is a label describing a mental syndrome. In my opinion transsexuality and gender dysphoria in part share a common driver, probably the presence of testosterone or more likely of testosterone surges, operqating on brain circuits. Testosterone surges, acting upon the brain in a nonsexual way that is independent of the genome, exert their influences in a high-speed fashion that pays attention to patterns as well as levels. It seems likely that testosterone surges, operating non-genomic only, stimulate the basal ganglia and other brain elements involved in executive processes and behaviors. We know that these brain regions are sensitive to testosterone. We know that for instance, that OCD worsens in the springtime, as testosterone levels rise. Interestingly when we treat transsexuals with long acting hormone pellets that effectively & consistently reduce testosterone to castrate levels, gender dysphoria vanishes only to reappear as these hormones ebb below a certain threshold level. In contrast, patients who obtain injectable feminizing hormones that wax and wane and facilitate surging testosterone escapes, tend to be associated with a persistence in the gender dysphoria process even when the patient is being effectively feminized. To sum up, that's why I say that we don't treat transsexuality we treat patients experiencing gender dysphoria, a nasty experience which needs to be quelled.