Food is broken down in the stomach and the intestines.
The conditions that cause nausea after eating range from mild to severe. This article will outline:
- what these disorders are
- how to tell what is causing the nausea
- how to avoid or treat it
Contents of this article:
How the digestive system works
The digestive system refers to a collection of organs that work together to break down food and drink. They digest what is consumed, turning nutrients into energy that the body can use for functioning or store for later use.
The digestion process begins in the mouth, where food is broken down so that it can be swallowed. Food then travels down the food pipe (esophagus) towards the stomach and intestines.
The digestive juices in the stomach and intestines break down the food for the final time and extract the nutrients. The waste passes into the large intestine for excretion through the anus.
Any problems during this digestive process can cause nausea after eating.
Symptoms will often develop in the stomach or upper abdominal area, where the large-scale breakdown of food begins.
Sometimes the body reacts to these problems by forcibly emptying the stomach, usually through vomiting. The problem can sometimes be identified by the color of the vomit. For example, a bright yellow or dark green color may indicate a problem in the small intestine.
Causes of nausea after eating
Causes of how nausea develops after eating include:
Hormonal changes often occur during pregnancy, which induce feelings of nausea at any time of day, frequently in the morning.
Some pregnant women will experience nausea before eating a meal. Others will feel nauseated immediately after eating. Sometimes this continues throughout the day.
Feelings of nausea will typically start during the second month of pregnancy. Nausea during pregnancy is not harmful to either the baby or mother and will usually resolve by the fourth month of pregnancy.
Elevated hormone levels in pregnancy can cause changes to the digestive system and the body, which means food spends longer in the stomach and small intestine. It is possible that this may also contribute to nausea after eating in pregnancy.
The hormones of pregnancy can relax the connection between the esophagus and stomach, causing an increase in acid reflux, which can contribute to nausea. A heightened sense of smell during pregnancy can also make nausea worse.
Food can become contaminated through not being cooked thoroughly or stored incorrectly. Consuming contaminated food can cause food poisoning.
Bacteria (or in some cases, viruses) are usually the cause of contamination. Either can induce feelings of nausea within hours of eating.
Viral infections of the digestive tract, such as "stomach flu," can also cause nausea after eating.
People can get these viruses from:
- close contact with another person infected with the virus
- eating contaminated food and drinking water
These viruses are highly contagious and cause inflammation to the stomach and intestines. They can lead to:
Food intolerances or allergies
Some people have an intolerance to certain foods, which means that the body has difficulty digesting them.
Some food intolerances can cause a person to feel nauseated after eating.
Food intolerances do not involve the immune system but can cause nausea hours after the food is eaten. Common sources of food intolerances include:
- foods that contain lactose, such as dairy products
- gluten, such as most grains
- foods that cause intestinal gas, such as beans or cabbage
Food allergies occur when the body mistakenly identifies proteins found in certain foods to be a threat, triggering an immune system response.
Nausea caused by a food allergy can occur seconds or minutes after eating. It is often accompanied by a host of other symptoms, such as swelling to the face or lip and difficulties breathing or swallowing. These types of reactions are emergencies and require immediate medical attention.
Nausea after eating and other gastrointestinal problems may occur when an organ within the digestive system stops functioning properly.
For example, gastroesophageal disease (GERD) occurs when the ring of muscle between the esophagus and stomach malfunctions, causing stomach acid to enter the esophagus.
GERD causes a burning sensation throughout the esophagus known as heartburn and may be a cause of nausea after eating.
The gallbladder is responsible for releasing bile to aid in digesting fats. Gallbladder diseases impair the proper digestion of fats and can cause nausea after eating meals high in fat.
The pancreas releases proteins and hormones necessary for digestion. If this organ becomes inflamed or injured, known as pancreatitis, nausea often occurs along with other intestinal symptoms and pain.
Irritable bowel syndrome is a chronic condition that can cause bloating and increased gas. In some people, this can lead to nausea after eating.
Nausea after eating could also be a sign of arteries in the intestines narrowing. This narrowing of blood vessels restricts blood flow. Nausea after eating can be accompanied by intense stomach pains and may indicate a condition known as chronic mesenteric ischemia. This condition can suddenly worsen and become life-threatening.
Migraines can also cause nausea after eating, which can be accompanied by intense stomach pain, vomiting, and dizziness.
Psychiatric or psychological
Anorexia nervosa can cause nausea due to excess stomach acid or starvation. Bulimia nervosa can cause nausea after eating from a compulsion to vomit any food consumed.
Some people are highly sensitive to particular movements or motion, which can make them feel nauseated. Eating food before or after experiencing motion can intensify nausea in individuals with motion sickness.
Other symptoms, which cause nausea after eating that indicate an underlying condition:
loss of appetite
head and muscle aches
loss of appetite
bloating or gas
swelling - typically on the face or throat
shortness of breath
hay fever-like symptoms, such as sneezing
bloating or gas
pain, typically in upper-right abdomen
|Irritable bowel syndrome||diarrhea
bloating or gas
|Acute pancreatitis||pain in upper left or middle of the abdomen, often through to the back
abdominal pain after eating
When to see a doctor
Typically, nausea after eating is not related to a serious condition. If it continues for more than 5 days or if some of the symptoms mentioned above occur together, people should contact a doctor to rule out an underlying condition.
Children who experience nausea after eating may need more attention. Contact a doctor if:
A nauseated child may also exhibit other symptoms that require medical attention.
- a child under 6 months old is vomiting
- a child over 6 months old is
- vomiting and has a fever over 101.4°F
- a child has been vomiting for more than 8 hours
- a child vomiting blood
- a child has not produced urine over 8 hours
- a child is abnormally sleepy
- a child has had abdominal pain for 2 hours
- a child has a headache
The causes of nausea are wide ranging. But recording exact times of nausea and food consumed can help a doctor make a diagnosis.
Depending on the suspected cause, getting a full diagnosis could involve:
- blood or urine tests
- skin tests
- swallowing tests
- a colonoscopy or upper endoscopy
- a CT scan or MRI of the abdomen
Treatment and outlook will depend on the diagnosis and can vary greatly. For example, people with GERD or heartburn may need treatment with acid blocking medication or antibiotics for the stomach bacteria, H. pylori.
People with a history of allergic or intolerant reactions should avoid certain foods. In the case of a stomach virus, people should stay well hydrated and eat bland foods once nausea decreases. More severe conditions, such as gallbladder disease, may require surgery.
Some tips that can help to prevent nausea after eating include:
- sticking to easy to digest foods, such as crackers, white rice, or dry toast
- trying chewing gum, mints, ginger ale, ginger gum, or ginger candy
- avoiding milk or high-fiber foods
- drinking liquids regularly but in small quantities until nausea improves
- limiting eating when nauseated while continuing to drink
- eating smaller, more frequent meals