@Valentijn posted on another thread: I have delayed OI - I don't faint on standing or (unless I have a new bug or something) feel dizzy but can't stand for long and have to lie down regularly during the day and have my feet up for most of the rest of the time. I've done the poor man's tilt test and come close to the POTS criteria but not close enough to get a diagnosis in the UK (I fail because I don't immediately collapse). However, if I keep standing, my heart rate continues to rise and rise. My impression is that 'delayed OI' isn't widely recognised as a diagnosis, but that doesn't seem to stop it from significantly disabling me! And Valentijn's post suggests this is common in ME. Are clinicians/researchers missing an important symptom? Should we be raising the issue? Are different treatments required from treatments for the more usual forms of OI?