When dizziness and nausea becomes severe enough to cause you to vomit and\or pass out, that is an Adrenal Crisis. Emergency Responders are trained to give an injection of 100 mgs. of Hydrocortisone when someone has passed out and has a history of Adrenal Insufficiency.
Salt craving is usually a sign of adrenal insufficiency. Low sodium will cause extreme fatigue, nausea and eventually vomiting, if it is severe enough. It is important to find out what your sodium\potassium ratio is. Having too much salt is as dangerous as too little.
Definitely, eat a little sea salt when you feel nauseous, and hopefully it will help.
Sometimes, you are getting enough salt, but your body is not absorbing it correctly. An aldosterone level test would show this.
If your BP drops, and you start to get sick, that can become life threatening quickly. If you start to vomit, get medical help ASAP. An ER can help you get steroids, fluids and treat the source if it is an infection.
I carry around 100mgs of steroids in case of emergency.
Sadly, not everyone is trained. I was in a hospital earlier this year and almost died - even though I was fine when I went in, but when I got a fever from the treatment, the resident did not think *I had enough symptoms of an adrenal crisis* so despite my medic alert bracelet, written instructions from a doctor that I carry that explain I have no adrenals (ergo, any sickness is an adrenal crisis), they waited 5 hours to give me only 80mgs after being threatened with a law suit... by that time, my RBC, WBC, potassium, magnesium, sodium etc. etc. all hit the floor and surprise - I also almost went into cardiac arrest. All this from a 103.5 fever. The next day, the doctor that I told them to page, finally arrived, and gave me 250mg of steroids. I felt like crawling the walls.
My endo wants me to go to the ER every time I toss my cookies but I refuse. I take extra cortef, push fluids, take extra salt and rest and so far I am ok after a few days. If I cannot stop the vomiting, I would have to go but my docs do prescribe anti-emitics which I take so that helps a lot.