Nausea and Vomiting - Nausea - Causes and Symptoms

Nausea is an uneasiness of the stomach that often precedes vomiting. Vomiting is the forcible voluntary or involuntary emptying ("throwing up") of stomach contents through the mouth.

What Causes Nausea or Vomiting?
Nausea and vomiting are not diseases, but they are symptoms of many conditions such as:

Motion sickness or seasickness
Early stages of pregnancy (nausea occurs in approximately 50%-90% of all pregnancies; vomiting in 25%-55%)
Medication induced vomiting
Intense pain
Emotional stress (fear)
Gallbladder disease
Food poisoning
Infections (such as the "stomach flu")
Overeating
A reaction to certain smells or odors
Heart attack
Concussion or brain injury
Brain tumor
Ulcers
Some forms of cancer
Bulimia or other psychological illnesses
Gastroparesis (a condition often seen in people with diabetes)