Vomiting and nausea can be caused by many factors, including stomach flu, eating too much food, drinking too much alcohol, food poisoning, motion sickness, pregnancy, acid reflux, viral infection, brain tumors, brain injury, or other illness.
If the vomiting and nausea is caused by food poisoning (ate something that contains chemical, toxic or other poisonous ingredients), you should immediately induce vomiting to have that stuff out. In this situation, you should not try to stop vomiting. If the emergency medical services is not available, you should induce vomiting without a delay. Otherwise, if the poisonous stuff goes into your intestines, it will cause serious, even life-threatening result.
Please note, you may use a treatment to stop vomiting and nausea only when it is not caused by food poisoning. 
How to treat a vomiting and nausea caused by stomach flu or internal coldness:
– Eat a piece of fresh ginger
– Or use some fresh ginger (or ginger powder) to make a tea, and drink it
– Or use a pinch of black pepper to make a tea, and drink it
How to treat a vomiting and nausea caused by early pregnancy morning sickness:
– You may drink a ginger tea to relieve it. Do not use black pepper. Black pepper is not recommended in pregnant women
How to treat a vomiting and nausea caused by motion sickness:
– Use some peppermint leaves to make a tea, and drink it
– Rub a few drops of peppermint oil to your temples and philtrum (the area between upper lip and nose)
– Eat a peppermint candy
For a vomiting and nausea caused by other factors, seek a physician immediately.
For more information about home remedies for vomiting, go to Natural Remedies Center: http://www.naturalremediescenter.com/treat/vomiting/
