What Is Nausea?
Nausea is queasiness of the stomach, with a sensation of the urge to vomit. Nausea is a very nonspecific symptom that can occur with a great many number of diseases and conditions. Nausea can occur due to pain, infections (like influenza or viral gastroenteritis), migraine, inner ear disease, motion sickness, food poisoning, or emotional stress. Some of the other conditions associated with nausea are heart attack, gallbladder attack, intestinal obstruction, meningitis, and pancreatitis. Nausea is also a common symptom of early pregnancy. Nausea occurs as a side effect of some medications.
Nausea is often accompanied by vomiting. Other associated signs and symptoms depend on the exact cause of the nausea and can include abdominal pain or cramping, diarrhea, constipation, fever, dizziness, chest pain, bloating, heartburn, and decreased appetite.
Nausea Symptoms and Signs
Nausea is a feeling of unease that frequently includes an upset stomach, dizziness, and anxiety. There is often an urge to vomit. This sensation often feels as if it comes from the stomach, but it is mostly controlled by the brain.
Vomiting, however, frequently improves the sensation of nausea, at least temporarily. Vomiting occurs when the stomach forcefully expels its contents out of the mouth. When vomiting continues after all the food and liquid has been forced out, it is called the dry heaves.
When vomiting leads to dehydration from loss of fluids, the affected person may have increased thirst, dry lips, and dry mouth. The person may not urinate often or urine will be darker in color. In children, signs of dehydration include dry lips and mouth, sunken eyes, rapid breathing, lethargy, and dry diaper, indicating the child is not producing urine.
What Are Other Symptoms and Signs Related to Nausea?
- Stomach Cramps
- Abdominal Pain
What Causes Nausea?
Nausea and vomiting are controlled by the same parts of the brain that control involuntary bodily functions. Vomiting is actually a reflex triggered by a signal from the brain.
The signal to vomit can result from several stimuli such as smells, taste, various illnesses, emotions (such as fear), pain, injury, infection, food irritation, dizziness, motion, and other changes in the body, specifically these:
- Food poisoning
- Certain viral infections
- Motion sickness (car sickness, seasickness)
- Vertigo (the sensation that the room is spinning around)
- Head injuries (such as a concussion or bleeding injury)
- Gallbladder disease
- Migraine (a severe form of headache)
- Brain tumors
- Brain infections (such as meningitis)
- Hydrocephalus (too much fluid in the brain)
- Side effects of anesthesia used for surgery
- Stomach problems such as blockage (pyloric obstruction, a condition that causes forceful spitting up in infants)
- Bleeding into the stomach from different causes
- Infection, irritation, or blockage of the intestines
- Low or high body chemicals and minerals
- Presence of toxins in the body
- Excessive alcohol intake
- Alcohol from beer, wine, and liquor is turned into a chemical (acetaldehyde), which results in the sensation of nausea that is felt the next morning, known as a "hangover"
- Nausea and vomiting occur frequently in pregnancy. Morning sickness usually happens in the first few months but sometimes can last throughout the pregnancy.
Nausea and vomiting are common side effects of some medications. Usually nausea is not an allergy to a drug (which is a severe reaction that can include skin rash or trouble breathing), but an unwanted side effect of the medicine. Some medicines such as those used in cancer treatment (chemotherapy), antibiotics like erythomycin, and strong pain killers are well known to cause nausea and vomiting.