Dd first experienced a full day of vomiting in September. She could not even keep water down.
About three weeks after the first spell of all day vomiting, she experienced another day of uncontrolled vomiting. On this occasion there were coffee grounds in her vomit so we went to A&E and they took bloods. White blood cell count was high. Her thyroid measurement was also off. When retested at her GPs a few weeks later white blood cells were then low and thyroid normal.
Since then, she will sometimes vomit in the morning when she first wakes up and then it settles (she is not pregnant - no sexual partner), on other days the vomiting continues. Last Monday (8 days ago) she vomited first thing, in the car on the way to work (I drive her) and a couple of times on shift until she had to come home early. Between last Monday and today she has felt largely fine, but has hit a vomiting spell again today (6 x and counting).
NHS hasn't quite sussed it. GP has done repeat blood tests after the A&E visit and has prescribed her Lansoprazole for GERD but we (and the GP) are not convinced its acid reflux.
This is affecting her mental health and her job.
Any ideas what it might be (I am clutching at straws that there might be someone here who has experienced similar), because the GP doesn't seem to know 
When she vomits she goes very hot immediately prior and cold directly afterwards, and if she gets up to walk her stomach contracts and she hunched over