do you know if you have gastroesophageal reflux (gerd)? because what you're throwing up may not be mucus but rather stomach acid that's been sitting in your esophagus all night. people with acid reflux disease may not have classic symptoms of heartburn. instead they may hack up yellowish "mucus" looking stuff in the morning (though not usually via actual vomiting) or exhibit tooth decay on their back molars. if you're truly vomiting i'd suggest you see a medical professional. a number of conditions could be causing this and you can only receive an accurate diagnosis if you're examined by your primary health care provider. hope this helps!
for a while now i have been throwing up mucus in the mornings. why is this? should i be concerned?