Nausea and Vomiting
Nausea is an uneasiness of the stomach that often comes before 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 (such as fear)
- Infections (such as the "stomach flu")
- A reaction to certain smells or odors
- Heart attack
- Concussion or brain injury
- Brain tumor
- Some forms of cancer
- Bulimia or other psychological illnesses
- Gastroparesis or slow stomach emptying (a condition often seen in people with diabetes)
- Ingestion of toxins or excessive amounts of alcohol
The causes of vomiting differ according to age. For children, it is common for vomiting to occur from a viral infection, food poisoning, milk allergy, motion sickness, overeating or feeding, coughing, or blocked intestines and illnesses in which the child has a high fever.
The timing of the nausea or vomiting can indicate the cause. When appearing shortly after a meal, nausea or vomiting may be caused by food poisoning, gastritis (inflammation of the stomach lining), an ulcer, or bulimia. Nausea or vomiting one to eight hours after a meal may also indicate food poisoning. However, certain food borne bacteria, such as salmonella, can take longer to produce symptoms.
Is Vomiting Harmful?
Usually vomiting is harmless, but it can be a sign of a more serious illness. Some examples of serious conditions that may result in nausea or vomiting include concussions, meningitis (infection of the membrane linings of the brain), intestinal blockage, appendicitis, and brain tumors.
Another concern is dehydration. Adults have a lower risk of becoming dehydrated because they can usually detect the symptoms of dehydration (such as increased thirst and dry lips or mouth). But children have a greater risk of becoming dehydrated, especially if they also have diarrhea, because young kids are often unable to communicate symptoms of dehydration. Adults caring for sick children need to be aware of these visible signs of dehydration: dry lips and mouth, sunken eyes, and rapid breathing or pulse. In infants, also watch for decreased urination and a sunken fontanelle (soft spot on top of the baby's head).
Recurrent vomiting in pregnancy can lead to a serious condition called hyperemesis gravidarum where the mother may develop fluid and mineral imbalances that can endanger her life or that of her unborn child.
Rarely, excessive vomiting can tear the lining of the esophagus, also known as a Mallory-Weiss tear. If the esophagus is ruptured, this is called Boerhaave's syndrome, and is a medical emergency.