What Causes Nausea After Eating?

There are many conditions that can make you nauseated after eating. Whether it’s a one-time illness, a food intolerance, or a stomach condition, determining the cause can help you avoid potential triggers and discover what to do to start feeling better.

Food allergies and intolerances

Certain foods, like shellfish, nuts, or eggs, can fool your immune system into identifying them as harmful foreign invaders. If you have a food allergy, your immune system launches a series of events that leads to the release of histamine and other chemicals when you eat one of these trigger foods.

These chemicals produce allergy symptoms, ranging from hives and mouth swelling to nausea. Other common food allergies include milk, wheat, soy, fish.

Food intolerances, unlike food allergies, are not life-threatening. But they can still cause uncomfortable symptoms like nausea, diarrhea, bloating, and other symptoms.

As much as 20 percent of the population may be affected by food intolerances. People commonly experience food sensitivities to dairy, gluten, food additives, and specific types of carbohydrates known as fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs).

Food poisoning

According to the Centers for Disease Control and Prevention (CDC), an estimated 1 in 6 Americans gets sick from food poisoning every year. The CDC says food poisoning can happen when:

• food is not heated to the necessary temperature
• the refrigerator is warmer than 40°F (4.4°C)
• cooking surfaces and hands are not cleaned prior to handling food
• when raw products like meat, seafood, poultry, and eggs come into contact with ready-to-eat foods.

Food poisoning symptoms like nausea, vomiting, and diarrhea typically start within 30 minutes to a few hours after you’ve eaten contaminated food. But some types of food poisoning cause symptoms that appear days or weeks later.

Learn more about the difference between a stomach bug and food poisoning.

Stomach virus

Norovirus, which is sometimes nicknamed the “stomach flu,” infects the intestines and triggers gastrointestinal (GI) symptoms like nausea and vomiting, as well as diarrhea. Symptoms usually start 12 to 48 hours after being exposed to the virus and typically last a few days.

This stomach bug is easy to both catch and spread. People can catch the virus through contact with virus particles in the vomit or feces of an infected person. For example, you can become infected by eating food prepared by someone with the virus or prepared on a contaminated surface.

Those who have recovered may continue to spread the virus for up to 2 weeks, and people who are infected but are asymptomatic can also shed virus particles.

You can also get this virus from food prepared with or sourced from contaminated water. This typically includes fruits, vegetables, and shellfish that are consumed raw, like oysters.

Pregnancy

One of the earliest physical signs that you’re pregnant is an uneasy, queasy feeling, which often starts during the second month of your pregnancy. Changing hormone levels trigger pregnancy nausea.

About 70 percent of pregnant women experience nausea. Though its official name is “morning sickness,” nausea can strike at any time of day, including mealtimes. Sometimes the smell or taste of certain foods is enough to make your stomach roll. The feeling is temporary, and it won’t harm you or your baby.

Less commonly, some pregnant people experience a more severe form of morning sickness called hyperemesis gravidarum. This condition causes frequent vomiting and can cause bodyweight loss, dehydration, and an imbalance in the nutrients your body needs.

If you experience extreme nausea and vomiting during pregnancy, talk with your doctor or obstetrician about options for treatment.

Acid reflux

A burning feeling behind your breastbone, known as heartburn, is the hallmark symptom of gastroesophageal disease (GERD), but this condition can cause nausea, too.

GERD happens when the muscular valve between your esophagus and stomach malfunctions, allowing stomach acid to leak up into your esophagus. This disease is common and affects about 20 percent of the adult population in the Western world.

You may also experience heartburn, indigestion, a feeling of fullness, or a sour taste in the back of your mouth, among other symptoms.

GERD may occur more frequently in individuals with hiatal hernia, a condition where a part of the stomach is pushed up into the chest cavity.

Anxiety and stress

Anxiety and stress don’t only take a toll on your emotions. They can affect your physical health, too — including your digestive system.

The Anxiety and Depression Association of America lists GI issues as a symptom of generalized anxiety disorder and panic disorders. Nausea can also be a symptom of social anxiety disorder and other phobias.

According to an older but well-cited 2009 review, some studies suggest a relationship may exist between gastrointestinal (GI) symptoms and anxiety and depression.

The digestive tract and the brain are connected by nerves. This is known as the gut-brain connection. When you’re stressed, hormones and chemicals are released into the body, where, over time, they may enter the digestive tract and have a negative, inflammatory effect on your gut microbiome.

Cancer treatment

Some chemotherapy drugs cause nausea as a side effect. Nausea can occur with medications taken orally and those given through an IV.

Chemotherapy can also cause anticipatory nausea and vomiting, where an individual becomes nauseated in the presence of certain triggers. The chance of developing anticipatory nausea and vomiting can increase with the number of chemotherapy sessions you’ve experienced.

The risk for nausea and vomiting after chemotherapy can depend on the different drugs used in your treatment, in addition to other factors.

According to a 2017 review, people under the age of 50 and women also have a higher risk of becoming nauseated by chemotherapy drugs. Individuals with a history of motion sickness, low alcohol intake, and vomiting during pregnancy may also have a higher risk.

If nausea after chemotherapy is especially troublesome, talk with your doctor about your treatment options.

Gallbladder diseases

Your gallbladder is an organ that sits on the upper right side of your abdomen. It helps your body digest fats. Gallstones and other gallbladder diseases can affect your ability to digest fats. As a result, you’ll feel sick to your stomach, especially after you eat a rich, fatty meal.

If you have a gallstone, you may also feel pain as the gallstone moves through to the bile duct. This pain can range from dull to intense or involve periods of increasing pain.

Sometimes, a gallstone can temporarily block the bile duct, resulting in biliary colic. The pain tends to increase 2 hours following a meal but may also occur at other times. Nausea and vomiting can accompany pain in your abdomen.

Cholecystitis is an infection of the gallbladder that happens when the gallbladder becomes inflamed. It causes more severe symptoms, including nausea and vomiting along with abdominal pain, fever, chills, jaundice (the yellowing of the eyes and skin), and more. This condition requires immediate medical attention.

Irritable bowel syndrome (IBS)

IBS is a chronic disorder of the GI tract that involves disturbances in bowel habits and abdominal pain. Symptoms can include abdominal pain, diarrhea, constipation, and nausea. It’s the most commonly diagnosed GI condition. Nausea is a common complaint in people with IBS.

IBS is classified as one of three types:

• diarrhea-predominant (IBS-D)
• constipation-predominant (IBS-C)
• alternating both diarrhea and constipation (IBS-A)

Sometimes, it may be brought on by a viral infection. In this case, it’s considered post-infectious IBS.

According to a review of IBS research, diet modification and exercise may help relieve some of IBS symptoms. Medications may also help, and relaxation techniques, acupuncture, and cognitive-behavior therapy have been shown to be helpful for some patients.

Treatment plans for this condition depend on the individual’s specific symptoms.

Motion sickness

Some people are especially sensitive to motion sickness. If you’re among them, the motion of a moving vehicle can make you feel sick. Eating before or after your ride can make your nausea even worse.

Motion sickness is caused by motion you haven’t adapted to. This means the signals your brain receives about your body movement and the environment around you may be in conflict. Sometimes, feelings of motion sickness can persist even after you’ve stopped moving.

You may also develop motion sickness from perceived motion while you’re standing or sitting still. This can occur if you view something in motion or take part in a virtual reality experience.

Nausea caused by motion sickness typically resolves after the triggering motion stops or within 24 hours.

Having nausea once in a while after you eat isn’t cause for alarm, but you should call a doctor if it doesn’t go away within a week. Call right away if you have any of these other more serious symptoms:

• blood in your vomit or stool — it may appear bright red but can also look like black stools or coffee grounds in vomit
• chest pain
• confusion
• diarrhea that lasts for more than a few days
• extreme thirst, little urine production, weakness, or dizziness, which are signs of dehydration
• fever of over 101.5°F (38.6°C)
• intense pain in the abdomen
• rapid heartbeat
• severe vomiting or trouble keeping food down
• jaundice or yellowing in the eyes or skin

In children under age 6, call their pediatrician if:

• vomiting lasts for more than a few hours
• you notice signs of dehydration, like few or no wet diapers, no tears, or sunken cheeks
• your child is running a fever higher than 100°F (37.8°C)
• diarrhea doesn’t go away

In children over age 6, call your child’s pediatrician if:

• vomiting or diarrhea lasts for more than a day
• you notice signs of dehydration, like your child isn’t urinating or producing tears or they have sunken cheeks
• your child is running a fever of over 102°F (38.9°C)
• your child has very low energy

Look for these other symptoms, which can help pinpoint the cause of your nausea:

Your doctor will ask you to describe your symptoms, including when you feel nauseated, how long the feeling lasts, and what seems to trigger it.

Consider keeping a food diary if you commonly experience nausea after eating and aren’t sure of the cause.

In addition to what you ate, note the symptoms you experienced, how long they lasted, and how soon after eating they started. Keeping a diary of what you eat and how you feel afterward can help your doctor make a diagnosis.

Depending on what condition your doctor suspects, you might need tests, like:

• blood or urine tests
• a skin test to see if you have food allergies
• upper endoscopy to see whether your esophagus is swollen, which is a sign of GERD
• CT, X-ray, or ultrasound scans to check your organs for signs of disease
• colonoscopy, flexible sigmoidoscopy, or upper or lower GI series to look for problems in your GI tract

The cause of your nausea will determine how you treat it.

Try these tips to avoid feeling sick after you eat:

• Suck on ice cubes or crushed ice.
• Avoid greasy, fried, or spicy foods.
• Eat mainly bland foods, like crackers or toast.
• Eat smaller meals more frequently, instead of three large meals that are spaced out.
• Relax and sit still after you eat to give your food time to digest.
• Eat and drink slowly.
• Serve foods cold or at room temperature if the smell of cooked food makes you feel queasy.

Your outlook will depend on what’s causing your nausea and how you treat it. Usually, nausea after you eat will get better once you address the source of the problem.