Nausea
From WebMD.com

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 .

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)
• 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 or slow stomach emptying (a condition that can be 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 young children have a greater risk of becoming dehydrated, especially if they also have diarrhea, because they often are 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 in which 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.

When to Call the Doctor About Nausea and Vomiting
Call a doctor about nausea and vomiting:

• If the nausea lasts for more than a few days or if there is a possibility of being pregnant
• If home treatment is not working, dehydration is present, or a known injury has occurred (such as head injury or infection) that may be causing the vomiting
• Adults should consult a doctor if vomiting occurs for more than one day,diarrhea and vomiting last more than 24 hours, or there are signs of dehydration.
• Take an infant or child under six years to the doctor if vomiting lasts more than a few hours, diarrhea is present, signs of dehydration occur, there is a fever, or if the child hasn't urinated for 4-6 hours.
• Take a child over age six years to the doctor if vomiting lasts one day, diarrhea combined with vomiting lasts for more than 24 hours, there are any signs of dehydration, there is a fever higher than 101 degrees, or the child hasn't urinated for six hours.

You should seek immediate medical care if any of the following situations occur with vomiting:

• There is blood in the vomit (bright red or "coffee grounds" in appearance)
• Severe headache or stiff neck
• Lethargy, confusion, or a decreased alertness
• Severe abdominal pain
• Diarrhea
• Rapid breathing or pulse

How Is Vomiting Treated?
Treatment for vomiting (regardless of age or cause) includes:

• Drinking gradually larger amounts of clear liquids
• Avoiding solid food until the vomiting episode has passed
• If vomiting and diarrhea last more than 24 hours, an oral rehydrating solution such as Pedialyte should be used to prevent and treat dehydration.
• Pregnant women experiencing morning sickness can eat some crackers before getting out of bed or eat a high protein snack before going to bed (lean meat or cheese).
• Vomiting associated with cancer treatments can often be treated with another type of drug therapy. There are also prescription and nonprescription drugs that can be used to control vomiting associated with pregnancy, motion sickness, and some forms of dizziness. However, consult with a doctor before using any of these treatments.

How Can I Prevent Nausea?
There are several ways to try and prevent nausea from developing:

• Eat small meals throughout the day instead of three large meals.
• Eat slowly.
• Avoid hard-to-digest foods.
• Consume foods that are cold or room temperature if you nauseated by the smell of hot or warm foods.
• Rest after eating with your head elevated about 12 inches above your feet.
• Drink liquids between meals rather than during meals.
• Try to eat when you feel less nauseated.

How Do I Prevent Vomiting Once I Feel Nauseated?
When you begin to feel nauseated, you may be able to prevent vomiting by:

• Drinking small amounts of clear, sweetened liquids such as soda or fruit juices (except orange and grapefruit juices, because these are too acidic)
• Resting either in a sitting position or in a propped lying position; activity may worsen nausea and may lead to vomiting.

To prevent nausea and vomiting in children:

• To treat motion sickness in a car, seat your child so he or she faces the front windshield (watching fast movement out the side windows can make the nausea worse). Also, reading or playing video games in the car could cause motion sickness.
• Don't let kids eat and play at the same time.

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