Merck Manual

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Some Causes and Features of Nausea and Vomiting

Some Causes and Features of Nausea and Vomiting


Common Features*


Digestive tract disorders

Significant abdominal pain

Abdomen that is tender to the touch

Abdominal imaging tests (such as x-rays, ultrasonography, and/or CT)

No bowel movements and no flatus

Cramping abdominal pain that comes and goes

Distended abdomen

Usually in people who are known to have a hernia or who have had abdominal surgery

Abdominal x-rays taken with the person in flat and upright positions

Vomiting and diarrhea

Little or no abdominal pain (except during vomiting)

Rarely fever or blood in stool

Normal abdominal examination

A doctor’s examination alone

Gastroparesis (poor stomach emptying)

Vomiting of partially digested food a few hours after ingestion

Often occurs in diabetics who have elevated blood sugar (glucose) or after abdominal surgery

A doctor’s examination

Abdominal x-rays taken when the person is laying down and when upright

Mild to moderate nausea for many days and sometimes vomiting

A general feeling of illness (malaise)

Loss of appetite

Mild discomfort in the upper right part of the abdomen

Blood tests

Vomiting and abdominal bloating

May occur after surgery, in severe illness, or with severe electrolyte disturbances

X-rays or CT scan

Ingestion of a toxin (there are many that cause vomiting―common examples include alcohol, aspirin, iron, lead, or insecticides)

Ingestion usually clear based on the person's history

Various other symptoms depending on the substance ingested

Depends on the substance ingested but may include blood tests and liver function tests

Brain and nervous system disorders

Injury clear based on the person's history

Often headache, confusion, and difficulty remembering recent events

CT of the head

Sudden, often severe headache


CT of the head

Spinal tap if CT results are normal

Gradual headache and confusion

Often fever and pain with tilting head forward

May cause a reddish purple rash of tiny dots on the skin (petechiae) if due to meningococcal meningitis§

Spinal tap (sometimes preceded by CT of the head)

Severe nausea and vomiting with headache and/or dizziness

CT or MRI of the head

Nausea and vomiting (sometimes severe) and sometimes weight loss

Usually develops after longstanding cannabis use

A doctor's examination

Urine drug test

Relief after a hot shower or marijuana cessation

Sometimes blood tests

Increased pressure within the skull (such as caused by a blood clot or tumor)

Headache, confusion, and sometimes problems with nerve, spinal cord, or brain function

CT of the head

A false sensation of movement (vertigo), rhythmic jerking movement of the eyes (nystagmus), and symptoms worsened by motion of the head

Sometimes ringing in the ears (tinnitus)

A doctor’s examination

Sometimes MRI

Usually a moderate to severe headache

Headache sometimes preceded by seeing flashing lights and blind spots (aura)

Sometimes sensitivity to light (photophobia) or temporary disturbances in balance or muscle strength

Often a history of repeated similar attacks

A doctor’s examination

Sometimes CT or MRI of the head and spinal tap (if results of the examination unclear)

Trigger clear based on the person's history

A doctor’s examination alone

Psychologic disorders (for example, anorexia nervosa and bulimia nervosa)

No diarrhea or abdominal pain

Vomiting that often occurs with stress

Consumption of food considered repulsive

A doctor’s examination alone

Systemic (bodywide) conditions

An increased volume of urine excreted each day (polyuria), excessive thirst (polydipsia), and often significant dehydration

Blood tests

Drug side effects or toxicity

Ingestion of a drug or substance clear based on the person's history

Depends on the substance ingested but may include blood tests

Often jaundice in advanced liver disease

Ammonia odor to the breath in kidney failure

Often in people known to have the disorder

A crude flapping motion of the hands (asterixis)

Blood and urine tests to evaluate liver and kidney function

Blood tests to determine the level of ammonia in the blood


Nausea and/or vomiting often in the morning or triggered by food

Normal examination (except the person may be dehydrated)

Often a missed or late menstrual period

Pregnancy test

Exposure usually clear based on the person's history

Severe nausea, vomiting, and diarrhea

A doctor’s examination alone

* Features include symptoms and the results of the doctor's examination. Features mentioned are typical but not always present.

† Although a doctor's examination is always done, it is mentioned in this column only if the diagnosis can sometimes be made by the doctor's examination alone, without any testing.

‡ Doctors usually do a urine pregnancy test for all girls and women of childbearing age.

§ Sometimes forceful vomiting (caused by any disorder or condition) causes petechiae on the upper torso and face, which may resemble petechiae caused by meningococcal meningitis, a particularly dangerous form of meningitis. People with meningococcal meningitis are usually very ill, whereas people with petechiae caused by vomiting are often otherwise quite well.

CT = computed tomography; MRI = magnetic resonance imaging.