Nausea

Nausea is the sensation of having an urge to vomit. Vomiting is forcing the contents of the stomach up through the esophagus and out of the mouth. The body has a few main ways to respond to an ever-changing, wide variety of invaders and irritants. Sneezing ejects the intruders from the nose, coughing from the lungs and throat, diarrhea from the intestines, and vomiting from the stomach.

Vomiting is a forceful action accomplished by a fierce, disgusting contraction of the diaphragm. At the same time, the abdominal muscles tighten against a relaxed stomach with an open "cardiac sphincter". The contents of the stomach are propelled up and out. Salivation may increase just before vomiting. Vomiting is a complex, coordinated reflex orchestrated by the vomiting center of the brain. It responds to signals coming from:

• The mouth, stomach, and intestines
• The balancing systems in the ear (motion sickness)
• The brain itself, including unsettling sights, smells, or thoughts

An amazing variety of situations can trigger vomiting, from a migraine headache to a roller coaster ride to a spoon down the back of the throat, (this stimulates the gag reflex). Sometimes, just seeing someone else vomit will start one vomiting. One should remember, however, that vomiting is common. Almost all children will vomit several times a year during their childhood. In most cases, it is due to a viral gastrointestinal infection or simply eating too much candy.

The following are possible causes of vomiting:

• Viral infections
• Medications
• Seasickness or motion sickness
• Migraine headaches
• Morning sickness during pregnancy
• Food poisoning
• Food allergies
• Brain tumors
• Chemotherapy in cancer patients
• Imbibing too much alcohol

Nausea derives from Latin and is the plural of nauseum. It has the same root as natation, the sense or act of swimming. The singular form of the word appears in English in phrases such as: "He talked about life insurance and nauseum", implying the speaker has said more than the listener wants to hear. Since nausea is already plural, it is not correct to write nauseas, for the same reason it is not correct to write datas, medias, or magmas.