But patients often report it doesn't alleviate nausea.

CNN: Richard Lacayo

Prior research had suggested that ginger supplements couldn't reduce nausea during chemotherapy, but Ryan says timing is everything: By giving the supplement three days prior to treatment--which had not been done in previous studies--the anti-inflammatory property of ginger had a head start on quashing queasiness.

CNN: Ginger may help chemo patients with nausea

If a patient is short of breath or can't keep fluids down because of nausea, these are signs of a problem that needs immediate attention, Zich said.

CNN: What to do if you have the flu

Three years later, Miller still can't exercise or be around large crowds without suffering from migraines and nausea.

WSJ: Cycling's Occupational Hazard

Tension headaches can sometimes be difficult to distinguish from migraines, but unlike some forms of migraine, tension headache usually isn't associated with visual disturbances (blind spots or flashing lights), nausea, vomiting, abdominal pain, weakness or numbness on one side of the body, or slurred speech.

CNN: Tension headache