What is nausea?

Nausea is an uncomfortable sensation in the upper abdomen, usually accompanied by a feeling that you are about to vomit. It is not defined as a disease, but may signal conditions ranging from mild and temporary to chronic and very serious. Because it has so many causes, almost everyone experiences it sometimes. The vagus nerve, which starts in the brainstem, winds through the neck and ends in the abdomen, is responsible for triggering nausea.

Sometimes a symptom of another condition and sometimes a warning sign, nausea can be caused by situations such as:

  • Migraine
  • Stress, anxiety and phobias
  • Road, sea and air travel (motion sickness)
  • Food poisoning
  • Flu or norovirus (stomach flu)
  • Gastrointestinal disorders such as irritable bowel syndrome
  • Various medicines
  • Pregnancy
  • Thyroid disorders
  • Eating disorders
  • Excessive alcohol consumption
  • Sensitivity to smells
  • Chemotherapy and cancer treatment

Food poisoning and stomach flu

Food poisoning or viral gastrointestinal infections are among the most common causes of nausea. Food poisoning occurs when we consume food or drink containing viruses, toxins or bacteria. Seasonal flu viruses also commonly cause nausea.

Pregnancy

About 50% of people experience nausea in the first few months of pregnancy. It results from changes in reproductive hormones. It is also a common side effect of birth control pills and may occur during monthly periods, again because of changes in hormonal balance.

Brain and sensory organ conditions

Any kind of brain injury can cause nausea. Glaucoma, a condition common in older adults involving increased eye pressure, may also cause it. Various conditions can affect the inner ear, causing dizziness, imbalance and nausea. Other common associated conditions include migraine headaches, meningitis, stroke and brain tumors.

Digestive organ problems

Many digestive conditions can cause nausea. Common examples include gastroesophageal reflux, hepatitis, pancreatitis, appendicitis, peptic ulcers and gallbladder problems. Constipation may also cause nausea.

Motion sickness

Motion sickness is triggered by repeated movements in changing directions. It commonly occurs on boats, in cars, on trains and on aircraft. Nausea is a common symptom.

Heart attacks in women

Like men, women can experience chest pain as a heart attack symptom. However, women are more likely to experience other symptoms such as cold sweats, dizziness and nausea.

Medical treatments

More than 50% of all medicines cause nausea as a side effect. The risk increases when several medicines are taken together. Cancer treatment with chemotherapy drugs routinely causes nausea. Some people also experience nausea after surgery in response to anesthesia.

Sensitivity to smells

Some people are very sensitive to smells. Exposure to perfume, certain food aromas or unpleasant odors can make them nauseous.

Mental health conditions

Mental and digestive health are closely linked. People with mental health problems may experience digestive symptoms, including nausea. Similarly, stress and personal phobias can cause nausea and various digestive problems.

CBD's effects on nausea

As mentioned at the beginning, nausea is a symptom or warning rather than a disease in itself. Unfortunately, research into CBD and nausea remains insufficient. However, studies of CBD and the endocannabinoid system (ECS) are helping scientists develop ideas and initiate new research.

The endocannabinoid system is a biological network of neurotransmitters and receptors responsible for many bodily functions, from mood to sleep quality. You can find our article “Everything you need to know about the endocannabinoid system” here.

A 2011 study suggested that manipulating the endocannabinoid system could help prevent both nausea and vomiting. It also stated that CBD relieved nausea and might even prevent it from occurring. This suggests CBD could function as an antiemetic, a medicine affecting the nerve center controlling vomiting.

Another study in 2013 suggested CBD might help regulate nausea because of its effects on the endocannabinoid system. It concluded that CBD had strong potential as an additional therapy for various health complications causing nausea.

A 2015 study in mice suggested various cannabinoids might help suppress acute and anticipatory nausea associated with chemotherapy and other therapeutic treatments.

Does THC work for nausea?

Nabilone and Dronabinol, two synthetic versions of the naturally occurring cannabis compound THC (delta-9-tetrahydrocannabinol), have been widely used with FDA approval to control nausea and vomiting since 1985. According to Roger Pertwee's “Handbook of Cannabis”, Dronabinol is the best option for mild to moderate chemotherapy-related nausea, but is not effective enough against nausea and vomiting caused by stronger chemotherapy medicines.

Whether natural or synthetic, THC blocks serotonin binding at receptor sites and interacts with receptors in the reflex pathways responding to nausea and the dorsal vagal complex in the brainstem.

However, synthetic cannabinoids, like THC, can cause paranoia, trigger mood changes and confusion, and increase anxiety. Synthetic THC may increase appetite and make losing weight difficult. It can also have the opposite effect and cause nausea and vomiting.

Differences between CBD and THC regarding nausea and vomiting:

  • Both block serotonin binding to receptors and relieve nausea.
  • Both prevent retching.
  • As a psychoactive cannabinoid, THC may cause unwanted side effects.
  • THC is harder to prescribe than CBD.
  • CBD is not psychoactive.
  • CBD is more readily available today.

The limited research available suggests CBD has the potential to help relieve nausea or prevent it entirely. Given the numerous side effects of conventional anti-nausea medicines, CBD could serve as a very good alternative.

However, since nausea is usually a symptom of another disease or condition, CBD is unlikely to be the sole answer. Particularly if you are receiving drug treatment, consulting your doctor before making CBD a daily routine is the best course.

Click to read our article about using CBD with other medicines.

We wish you good health.