Nausea

Nausea can be acute or chronic, physical or psychological and caused by conditions, such as food poisoning, peptic ulcers, motion sickness, pregnancy and brain disorders. It is extremely common in the first trimester of pregnancy. It could also be seen as a side effect of certain medications, or due to chemotherapy and radiation therapy.

Causes #

Nausea is not a disease in itself. It occurs as a symptom of various diseases. Disturbances in the gastrointestinal tract, inner ear, or chemoreceptors (which are cells sensitive to chemicals) generate signals of being sick in the brain. The feeling of nausea is then produced as a response to these disturbances.

Some common causes of nausea include:

Gastrointestinal conditions #

Any issue that interferes with the normal functioning of the stomach and the gastrointestinal tract can lead to nausea. These issues are:

• Stomach infection or gastroenteritis

• Food poisoning

• Gastric ulcers

• Appendicitis

• Hyperacidity

• Intestinal obstruction

• Cholecystitis

• Crohn’s disease

• Gallstones

• Gastroesophageal Reflux Disease (GERD)

• Irritable bowel syndrome

• Allergy to certain foods, like milk

• Indigestion (or excessive food intake)

Ear and balance disorders: #

• Motion sickness

• Meniere’s disease

• Ear infection or otitis media

• Vestibular neuritis

Pregnancy #

Morning sickness or the feeling of nausea is a common occurrence in pregnancy especially during the first trimester.

Side effects of medications or therapies #

Nausea can occur as a side effect of certain medications, such as chemotherapy drugs, NSAID painkillers, anesthetic drugs, and radiation therapy.

Self-inflicted #

Sometimes, nausea and vomiting can be self-inflicted in severe eating disorders like anorexia or bulimia.

Other illnesses #

The feeling of nausea is also seen with other health conditions, such as:

• Allergy or anaphylaxis

• Hyperthyroidism

• Meningitis

• Encephalitis

• Hydrocephalus

• Hepatitis

• Migraine

Diagnosis Of Nausea #

A single episode of nausea does not require any immediate diagnosis, as it is often self-limiting and can be easily cared for at home. A detailed evaluation of nausea is necessary when symptoms of nausea are recurring or chronic. A detailed history and clinical examination (including the eye and/ ear) with some specific investigations listed below help in identifying the underlying cause of nausea:

Lab Tests: Laboratory tests include-

• Complete Blood Count (CBC) to check for causes like anemia or active infections.

• Serum Electrolyte to evaluate the balance of electrolytes, such as sodium and potassium in the body.

• Protein Total, Serum checks the levels of human proteins, such as albumin, globulin, and the overall nutritional status.

• Pregnancy Urine Test in females of reproductive age to check for suspected pregnancy.

• Liver Function Test to check for the health of the liver and other possible causes of dysfunction of the liver.

• Tuning fork test: It is a screening test that uses a tuning fork to assess hearing loss which could be the cause of nausea.

• Nystagmus: It is a condition where a person cannot control eye movement.This can lead to dizziness or nausea, and also vision problems, as the person is unable to hold a steady gaze.

• Uremia test: It is a clinical condition which is characterised by high levels of urea in the blood. Nausea and vomiting may be caused by encephalopathic (damage or disease that affects the brain) or neurologic disorders (diseases of the brain, spine and the nerves that connect them) associated with uremia.

• Kidney function test (KFT): As the kidney health declines, some non-specific symptoms develop such as vomiting, nausea, weakness and tiredness.

Prevention #

• Eating fresh food, which is not spicy and oily.

• Eating smaller portions throughout the day instead of larger meals.

• Drinking liquids between two meals.

• Avoiding activities that trigger motion sickness, such as joyrides, traveling long distances via road, etc.

• Resting in a sitting position or elevated position after meals.

• Avoiding pain killers like NSAIDs above the prescribed dosage.

• Avoiding strong smells, such as deodorants, perfumes, or cooking odors, if they trigger nausea during pregnancy.

Treatment #

Treatment Of Nausea

Mild episodes of Nausea and vomiting do not require medical treatments as they often resolve on their own. For chronic or severe nausea, the following treatment options are available.

Symptomatic relief for nausea #

Antiemetic medicines #

Antiemetic medicines help to control nausea and prevent vomiting. These are the first choice of treatment suggested to provide relief from the symptoms of nausea. They work by blocking the action of the neurotransmitter receptors involved in causing vomiting. Some of the common examples of antiemetic medicines include:

• Domperidone

• Ondansetron

• Prochlorperazine

• Aprepitant

Antiemetics for morning sickness #

To treat morning sickness, which is a common symptom seen in early stages of pregnancy, a combination of anti-nausea medicines are recommended. For example, doxylamine + Vitamin B6 (Pyridoxine), a combination drug which is used to treat and prevent nausea and vomiting during pregnancy. Doxylamine is an antihistamine that blocks the action of certain natural substances in the body that may contribute to nausea and vomiting. Vitamin B6 is also known to have anti-nausea action. Your doctor may recommend the dose based on the severity of your symptom.

Antihistamines #

This class of medicines reduces or blocks the chemical histamine which is associated with allergy. These are helpful in treating nausea caused due to motion sickness or vertigo. Examples include:

• Promethazine

• Meclizine

Anticholinergic medications #

This class of medicines acts by blocking the action of the neurotransmitter acetylcholine. This chemical is known to play a key role in managing numerous body functions. It also helps to control nausea and vomiting.

Prokinetic drugs #

This class of medicines comes under prescription medicines. They promote normal contraction of the intestine and help in the emptying of the stomach. These are commonly recommended for people with GERD and given mostly in combination with medications that lower acid production in the body such as PPIs and H2 receptor blockers. Examples include:

• Metoclopramide

• Itopride

Treatment of underlying cause #

This includes treating the underlying cause of nausea such as:

• Stomach infections with antibiotics

• Vertigo with antivertigo drugs

• Hyperacidity with antacids

• Migraine with triptans

• Chemotherapy side effects with anti-nausea drugs

Supportive Care #

This includes supportive care with fluids and Oral Rehydrating Solutions (ORS) to replenish the loss of electrolytes in the body. These help in cases where the patient has lost excessive fluids due to vomiting and shows signs of dehydration.