Hi I’m new to this forum, thanks in advance for any advice. I have this problem; whenever I play high notes (for my range) from B just below the high C to above, my throat will swell considerably, about 1 to 2 cm outwards; it occurs at the part of my throat below my jaws, just above my adam’s apple. Or rather, the area known colloquially as double chin; except that I’m really really skinny, have a very sharp jawline and have no semblance of fats below the jaw. It’s gotten to the point where my band-mates are pointing out to me that I’m over-exerting my throat; using the wrong method of playing, instead of using diaphragm to push out the air, I'm straining my throat to push the air out. However, I’ve tried to rectify this problem by attempting to play using my diaphragm, ‘squeezing’ out air using the abdominal area; I no longer feel strain on my throat except on really high notes. (Am I supposed to strain my stomach when I’m playing high anyway? And just how does it feel when playing if one is using the diaphragm correctly?) Anyway, the problem has gotten worse in recent times; even at a mere middle C (an octave below high C) my throat/chin will start swelling already; by watching myself using a mirror. My question is, is throat swelling considered to be normal in the course of trumpeting? (With regard to my swelling of 1-2cm). And how does one know if he/she is using diaphragm blowing correctly?