Oak Street Health is part of CVS Healthspire™

9 Common Causes of Constant Nausea

Written by 
Angela Myers
Reviewed by 
Anwar A. Jebran, MD

Article at a glance

  • Nausea isn’t a condition, but a symptom that is caused by an underlying problem. It is commonly experienced as a sick-to-the-stomach feeling and can lead to vomiting. 

  • When someone experiences constant nausea, there is usually an underlying, chronic condition that must be treated, such as a peptic ulcer or Irritable Bowel Syndrome. 

  • Nausea is commonly accompanied by other symptoms, such as vomiting, headaches, trouble keeping food down, constipation and diarrhea. 

When someone’s stomach is upset or there’s trouble in the digestive tract, it’s often classified as nausea. This common symptom is experienced by many people and in a variety of scenarios, such as after a long car ride or when experiencing a stomach virus. 

While the conditions that cause nausea are numerous, it’s often a fleeting condition. If episodes of nausea persist for more than a month, it’s referred to as chronic nausea. When nausea is constant, a doctor should be consulted to diagnose and provide treatment. 

What Is Nausea?

Nausea commonly refers to the sick-to-the-stomach feeling most everyone experiences at one point or another. It can be a complicated symptom to treat since causes and severity vary. Someone can feel nauseous after riding a roller coaster, because of acid reflux, or due to an ear infection. 

It’s important to note that nausea itself is not a medical condition; it is a symptom of a variety of conditions or responses to harmful substances, such as undercooked meat or certain medications. 

Acute Nausea vs. Chronic Nausea

There are many causes of nausea and often, this symptom goes away on its own. When nausea starts to improve in 24 hours, it’s considered acute nausea. 

Often, acute nausea is caused by one of the following issues:

  • A viral illness 

  • Food allergies

  • Motion sickness

  • Overeating

  • Food poisoning

If nausea lasts more than 24 hours or pops up consistently over weeks or months, it may be considered chronic. Sometimes, chronic nausea is constant, though it often manifests in episodes of nausea caused by an environmental or internal trigger. 

Chronic nausea usually stems from one of the following issues:

  • Inner ear infection or imbalance

  • Brain or spinal fluid problems

  • Abdominal or pelvic organ issues

When nausea is chronic, a doctor should be consulted to diagnose the condition and create a treatment plan. 

Most Common Cause of Nausea

According to the CDC, the most common cause of nausea is norovirus, a common stomach bug” that often goes away without treatment. Norovirus causes a viral illness known as gastroenteritis. While symptoms, including acute nausea, may be similar to the flu, norovirus is a different condition. 

Common Causes of Chronic Nausea

Illnesses, a food allergy, an acute digestive disorder, or motion sickness are all common causes of acute nausea since symptoms usually don’t linger for a prolonged amount of time. If nausea is chronic, there are many potential causes. 

Causes of constant nausea vary greatly, but some of the most common include:

  • Inflammatory Bowel Disease (IBD)

  • Irritable Bowel Syndrome (IBS)

  • Migraines

  • Motion sickness

  • Gastroesophageal reflux disease (GERD)

  • Peptic Ulcers/​stomach ulcers

  • Certain Medications and Cancer Treatment

  • Intestinal obstruction

  • Gastroparesis

  • Psychological conditions, such as bulimia 

  • Morning sickness” associated with the first trimester of pregnancy

Note: For a more complete list of all causes of chronic nausea, explore this table published in Therapeutic Advances in Gastroenterology. 


Bulimia, a common eating disorder, is a mental condition where someone feels the urge to throw up after eating. Someone with this condition binge eats and then forces themselves to throw up in hopes of losing weight. Long-term bulimics often experience chronic nausea after eating due to the habitual practice of throwing up after a large meal. Treatment for this condition is usually administered by a psychiatrist, psychologist, or psychotherapist. 


Gastroparesis is a condition that causes someone to feel nauseous and/​or full shortly after they begin to eat. Sometimes referred to as delayed gastric emptying, gastroparesis is a disorder that stops food from moving from the stomach to the small intestine. 

It causes slow stomach emptying or hinders the stomach from emptying properly. Gastroparesis can also cause unexplained weight loss and other issues in the digestive system. This condition can have many underlying causes, or could be a complication of diabetes, and a medical provider must diagnose and create a treatment plan for gastroparesis. 

Peptic Ulcers Disease:

Peptic ulcers, or stomach ulcers, can cause abdominal pain, nausea, vomiting, and bloating after eating a meal. However, many with these ulcers don’t display symptoms until there’s an external trigger, such as nonsteroidal anti-inflammatory drugs (NSAIDs) or stress. 

Once triggered, the ulcer may trigger stomach acid to eat the small intestine or stomach, causing severe stomach sores and pain. Typically, doctors recommend medications, such as H2 blockers and proton pump inhibitors (PPIs), to heal peptic ulcers. 

Gastroesophageal Reflux Disease (GERD)

When nausea is accompanied by heartburn after eating, GERD may be to blame. Someone with this condition experiences their stomach contents return to the esophagus, causing a burning sensation in the chest. Often, doctors recommend lifestyle changes and over-the-counter medications to manage GERD symptoms. 

Intestinal Obstruction

When stool cannot move through the intestines, intestinal or bowel obstruction may be present. Accompanying symptoms include severe intense pain, vomiting, bloating, and constipation. Often, surgical interventions, such as intestinal obstruction repair, are needed to treat this condition. 

Certain Medications & Cancer Treatment

Chemotherapy, other cancer medications, and prescriptions for other conditions can cause chronic nausea. Radiation therapy on the brain, liver, or gastrointestinal tract often causes chronic nausea as well. When medications or cancer treatments are the cause of nausea and vomiting, you should consult a healthcare provider. They can work with you to manage symptoms, alter one’s diet, and change other lifestyle choices. 

Morning Sickness

Morning sickness is a common pregnancy symptom experienced in the first trimester. While called morning sickness, nausea and vomiting from pregnancy can happen at any time of the day. To reduce the risk, pregnant people can try at-home remedies, such as eating dry toast when they wake up or crackers before they go to bed. An OB/GYN can provide more ways to manage vomiting and nausea from pregnancy. 

Inflammatory Bowel Disease (IBD)

Inflammatory bowel disease (IBD) refers to two conditions, Crohn’s disease and ulcerative colitis. Both are characterized by inflammatory changes of the GI tract and issues in the central nervous system, which can cause nausea, diarrhea, bloody stools, and fatigue. While the cause is unknown, IBD is due to a weakened immune system, and treatment often includes medication. In severe cases, surgery can remove damaged parts of a GI tract such as ulcers or fistulas.

Irritable Bowel Syndrome (IBS)

Irritable bowel syndrome (IBS) is a group of symptoms related to the gastrointestinal tract and bowel movements. Those with IBS often experience diarrhea, constipation, or both, along with nausea. IBS must be diagnosed by a doctor. Treatment usually includes medication and lifestyle changes, such as practices to improve mental health or adding probiotics to someone’s diet. 

Nausea Risk Factors

Depending on the underlying cause, some risk factors increase someone’s chances of experiencing nausea, such as: 

  • Certain medications and prescription drugs

  • Family history

  • Battling other digestive conditions

  • Chemotherapy

As someone ages, they may become more susceptible to certain causes of chronic nausea, like GERD or intestinal obstruction. 

Certain environmental factors or actions may also trigger nausea. The most common include strong smells and eating. Certain conditions are more likely to cause nausea after a meal or snack. These range from mental health concerns, like bulimia, to physical health conditions, including gastroparesis, peptic ulcers, and GERD.

Nausea is often experienced alongside other symptoms. The most common accompanying symptoms include:

  • Vomiting

  • Migraines

  • Weakened stomach muscles

  • Stomach pain

  • Diarrhea

  • Constipation

  • Dizziness

  • Uncomfortable chest pain

  • Persistent ear infections

  • Autonomic disturbances

  • Fatigue

Nausea can also cause mental health symptoms, with the most common being emotional stress or sleep problems. 

Nausea and Vomiting

90% of the time, nausea isn’t accompanied by vomiting, according to a 2019 study. When vomiting and nausea do occur, various conditions might be to blame. This symptom is more common in children, and often, it occurs when children experience acute nausea from a viral condition. 

If there are repeated episodes of vomiting, someone may be diagnosed with cyclic vomiting syndrome. Three of the most common causes of this syndrome include intestinal obstruction, certain medications and drugs, and morning sickness. 

Nausea and Migraines 

Migraines are a severe type of headache that affects the sensory nervous system. Often, they are accompanied by a variety of symptoms, such as nausea, vomiting, blurred vision, eye pain, head pain, and dizziness. Like nausea, migraines have many causes and a doctor should be consulted to determine the triggers and best treatment plan. 

Nausea, Diarrhea, and Constipation

Because nausea impacts the digestive tract, it can be accompanied by additional symptoms, such as diarrhea or constipation. Diarrhea is when someone’s bowel movements are loose and watery. It also causes people to go to the bathroom too much. Constipation is the opposite

If someone alternates between constipation or diarrhea, they may have IBS. Other causes of nausea which can cause diarrhea or constipation include food poisoning, viruses, and intestinal obstruction. 

Nausea, Stomach Pain, and Weakened Stomach Muscles

When nausea is chronic, it can weaken the stomach muscles over time. Gastroparesismore is most likely to weaken the stomach muscles. Many other causes of nausea don’t affect the stomach muscles at all.

Getting Rid of Nausea

Since the causes of nausea vary, treatment options do too. Often, the best way to get rid of nausea is to consult a doctor about a treatment plan for the specific underlying condition. Some over-the-counter medications may also help, such as antihistamines or pepto-bismol. Consult with a doctor before starting any medication for nausea. 

Some practices can offset the discomfort of nausea:

  • Stick to a bland diet: The BRAT diet (a diet of solely bananas, rice, apples, and toast) is a great way to ensure the body gets some nutrients, but won’t upset your stomach. 

  • Avoid certain foods: Spicy, fatty, or salty food may make nausea worse. Fast food should also be avoided. 

  • Drink plenty of fluids: Dehydration can make nausea worse. If keeping liquids down is difficult, try small, consistent amounts of clear liquid throughout the day.

  • Eat small meals: Instead of cooking a large breakfast, lunch, and dinner, eat smaller amounts of food more often. 

  • Avoid strong smells: certain smells or odors can lead to nausea.

Preventing Nausea

For those experiencing chronic nausea, prevention of future episodes is as important as eliminating current nausea symptoms. To prevent nausea, there are some steps to take and avoid. 

Those with chronic nausea should:

  • Consult a medical provider to determine the cause and a treatment plan for their condition.

  • Drink at least 8 to 10 cups of water each day to avoid dehydration.

  • Follow the treatment plan and any orders from your doctor.

  • Eat a plain diet with lean meat, and hot or warm foods. Avoid hard-to-digest foods to reduce inflammation caused by food.

Those with chronic nausea shouldn’t:

  • Eat large amounts of fatty or greasy foods. This is especially important to prevent vomiting.

  • Drink large amounts of caffeine, such as coffee and Coca-Cola, as this can aggravate the stomach.

  • Indulge in sweetened liquids and highly processed fruit juices.

  • Eat very spicy foods or foods with a strong smell

When to See a Doctor

While there are at-home prevention methods and treatments, many people need additional care from a doctor. Anyone experiencing chronic nausea should also create a non-emergency appointment with their preferred doctor to discuss potential causes and treatments. 

On top of scheduled appointments, contact emergency services or a medical professional immediately if experiencing nausea and:

For children, there are some additional signs to contact emergency services. These include:

  • A fever over 100 Fahrenheit 

  • Eight hours without urinating

  • Persistent earache.


Why do I feel nauseated all the time?

Nausea is a common symptom of many underlying conditions, such as migraines or intestinal obstruction. If someone feels nauseated for more than 24 hours, they should contact a healthcare provider to determine their specific condition and the best treatment options.

When should I be worried about constant nausea?

When experiencing nausea for more than 24 hours, consider contacting a doctor. It’s also important to seek help if experiencing nausea in shorter spurts over multiple weeks or months. For example, if someone always feels nauseous after eating or when they have a headache, they will want to make an appointment with a doctor who can diagnose and treat the underlying condition.

Why do I constantly feel nauseous but not throwing up?

It’s normal to feel nauseous, but not throw up. 90% of those who experience nausea don’t vomit. These are two separate symptoms, and vomiting usually only occurs in more severe cases or when there’s a trigger in the stomach, such as a food someone is allergic to or a specific medication.

What to do when you constantly feel nauseous?

When nausea is constant, it’s best to contact a doctor. Nausea is a symptom, not a medical condition in and of itself. As a symptom with many potential causes, a medical provider’s insight is needed to determine the exact cause and create an effective treatment plan.

Become a patient

Experience the Oak Street Health difference, and see what it’s like to be treated by a care team who are experts at caring for older adults.

Related articles

View all articles

Get access to care, right in your neighborhood.