context: Throwing up is no fun for kids. But it can worry you, too. A kid who's vomiting but doesn't have a fever could be dealing with any number of things. Knowing what else to look for can help you narrow down the reasons for your child's upset stomach --and get her the treatment she needs. This isn't the same as influenza (the flu). It's the term people use when they're talking about an illness called gastroenteritis. Most of the time, gastroenteritis is caused by a virus like rotavirus or norovirus. But you can also get it from bacteria like E. coli or salmonella. Although norovirus can sometimes cause a low-grade fever, you can also have it with no fever at all. Norovirus is contagious. If your child has it, she got it in one of three ways: She came into contact with someone who has it. She ate food that had the virus in it. She touched a surface with the virus on it, then touched her mouth or nose before washing her hands. Symptoms start 12â48 hours after your child gets the virus. Along with throwing up, she'll probably also have diarrhea, nausea, and stomach cramps. Most kids get better within 1 to 3 days. Sometimes throwing up is a sign your child is allergic to food she's eaten. Throwing up may be her only symptom, but there could also be others, like trouble breathing, hives, repetitive cough, wheezing, or trouble swallowing. Nine out of 10 allergic reactions are linked to the following foods: Peanuts Tree nuts (almonds, cashews, or walnuts, for example) Fish Shellfish (shrimp, for example) Eggs Milk Wheat Soy Very young babies who try milk, soy, certain grains, and some other solid foods for the first time are at risk for something called âfood protein-induced enterocolitis syndromeâ ( FPIES). It shows up 2 to 6 hours after they eat and makes them throw up many times. They may also have bloody diarrhea. Take your child to the doctor right away if you suspect she has FPIES. Anytime germs hitch a ride on food your kids eat, there's a chance they could get a food-borne illness (food poisoning). Some of the bacteria that usually hide in food are: Salmonella Listeria Campylobacter E. coli You can get food poisoning from almost any food, especially if it hasn't been cooked or stored correctly. The most common culprits are: Meat Poultry Eggs Shellfish Unwashed vegetables, like lettuce Your child might start throwing up within a couple of hours of eating contaminated food. Sometimes it can take a day or two for symptoms to show up. Usually, your child will also have nausea, watery diarrhea, and stomach pain. It's possible for food poisoning to cause fever, but it's common for it to cause throwing up with no fever, too. Symptoms can last anywhere from a couple of hours to several days. In newborns, it can be hard to tell whether she's throwing up or spitting up. Vomit usually comes out with more force than spit-up. Spit-up also tends to happen not long after a feeding. Your doctor can help you figure out which one you're dealing with. Forceful throwing up in babies is rare, but when it happens, it can be a sign of a blockage in your baby's intestines. It's also possible that your little one could have what doctors call âpyloric stenosis.â That means her stomach is too narrow for food to pass through. Both of these are serious problems you should see a doctor about right away. Kids hit their heads a lot -- especially when they're learning to walk or if they play sports. Anytime your child gets a head injury, it's important to watch for signs of a concussion. Throwing up is one of these signs. Others include: Losing consciousness Headache Blurred vision Trouble walking Confusion Slurred speech Trouble waking up Throwing up and other symptoms may not show up until 24 to 72 hours after your child hits her head. If your child takes certain medications on an empty stomach, it can make her throw up. Sometimes, vomiting is a sign you've given your child too much of certain medications. The most common meds that cause this are: Codeine Erythromycin Some birth control pills Some asthma medications, like theophylline Iron Acetaminophen Ibuprofen When your child's brain gets mixed signals about how she's moving, it can make her feel sick enough to vomit. For example, some kids might feel sick just watching a movie -- their eyes see motion, but their body doesn't feel motion. Carsickness is common in kids who are too small to see out the car window. Motion sickness usually starts with a tummy ache or a queasy feeling. Some kids may also sweat, lose their appetite, and not want to eat. Eventually, throwing up starts. It's a genetic condition. Your child is more likely to have motion sickness if one of her parents did. About 10% of school-age children deal with migraines. These headaches can happen in kids as young as 18 months old. They cause head pain, but it's also common for a migraine to make your child throw up. In addition, your child may have: Dizziness Nausea Sensitivity to touch, sound, and odors Experts aren't clear what causes migraines. It could be caused by something your child is around a lot. It's also genetic: If one parent has migraines, your child has a 50% chance of getting them. If both her parents have migraines, her chance of getting them goes up to 75%. It's true -- some kids throw up when they're stressed. It may be because some other health problem, such as an ear infection, is bothering them. Or your child might throw up after crying for a long time. A good way to tell if the throwing up is stress-related is if it happens only once or twice and they don't have any other symptoms like stomach pain or diarrhea.