Summarize this article:

If home remedies do not help to relieve your nausea within a day or so, or if you are vomiting, then call your physician right away to ensure that you don’t have a more serious problem. Nausea — often along with vomiting — is a common problem for many people.  The feeling of being “sick to your stomach” can be caused by a number of different things, including:  Food sensitivities or food allergies Bacterial or viral infections GastroEsophageal Reflux Disease (GERD) and heartburn Medications, especially chemotherapy and radiation treatments Pregnancy (morning sickness) Migraines and other headaches Motion sickness Pain If you have nausea with or without vomiting and it does not go away within 24 hours, call your physician for an appointment right away. If the nausea improves but you still have no appetite, have a headache or have severe stomach or abdominal pain, call your physician for advice. Nausea, especially when it’s accompanied by vomiting can be a sign of a more serious condition such as:  Appendicitis Intestinal obstruction or blockage Cancer Poisoning Peptic Ulcer Disease (PUD), especially if the vomit resembles coffee grounds

Summary:
Call your doctor if nothing helps or if you have other symptoms. Consider the cause of your nausea. Determine if you may need to seek medical attention.