This is one of the trickiest symptoms for us clinicians to deal with. Whereas prominent diarrhea invariably comes from the bowel, nausea / vomiting can be caused by conditions anywhere in the body. For example, try this for a smattering of possibilities (in random order):
- Simple stomach infection
- Brain Infections / Increased Intracranial Pressure (lethal)
- Acute Closed-Angle Glaucoma (blinding)
- Various Infections: Ear, Lung (Pneumonia), Kidney, Blood (lethal Sepsis)
- Abdominal Disease (anything from simple heartburn to lethal Peritonitis)
- Kidney Failure / Liver Failure / Diabetes (if severe)
- Abnormalities in sodium, calcium, etc. etc.
Anyone with nausea or vomiting may not be allowed inside a building without a Covid Test. But some patients need to be seen no matter what; every office or clinic has its own mechanism, maybe in a designated exam room, maybe sending them to an Urgent Care or E.R. If there are no other symptoms besides nausea or vomiting, Covid-19 is very unlikely. The rest of this topic assumes Covid is not a possibility.
We certainly don’t test for everything above all at once. Rather, we try to devise a manageable strategy to approach Nausea / Vomiting (to be abbreviated “N/V” from now on). See also Nausea / Vomiting for the clinician’s condensed thought-process when face-to-face with a patient.
First of all, we ask if there are any other symptoms elsewhere that might be a major clue, like earache, headache, painful urination, etc. If so, we use that symptom to structure our diagnostic approach.
The rest of this discussion presumes there aren’t any other significant symptoms — just N/V. Maybe the patient feels lousy, perhaps fatigued, but nothing more specific or helpful.
We start by defining the time frame, in terms of:
- Acute: <1 month
- Chronic: >1 mo.
- Recurrent: Symptoms come & go, with significant periods of feeling fine in between
Let’s begin with Acute N/V.
Before diagnosing the cause, we evaluate for Dehydration:
- The key sign is tachycardia — an increase in heart rate. We check this by taking the pulse, most accurately by listening to the heart by stethoscope (instead of feeling for a pulse at the wrist). Over 100 beats / min. is abnormal (unless the patient’s heart rate is always near 100), but 110-120 is much more convincing.
- If the heart rate is normal, we check to see if it goes up with standing. We have the patient lie down for 5 minutes, and count the pulse. Then we have them stand, & check it again in a minute-and-a-half. If the rate increases 20% (e.g. goes from 80 to 96), there’s dehydration. See Postural Vital Signs.
- A dehydrated patient might faint upon sudden standing, so we’re sure to hover nearby to catch and ease them back onto the exam table if necessary.
- Medicines like beta-blockers (atenolol, propranolol / Inderal, metoprolol, etc.) will interfere with assessment of heart rate (keeping the pulse slow).
- Not Urinating — A person vomiting who doesn’t urinate for 6-8 hours, & then just urinates a little, is likely dehydrated. If they don’t urinate for 12-24 hours, it’s dangerous.
A dehydrated person who looks sick needs IV fluids. If they perk up afterwards, the “looking sick” was simply from lack of fluids. On the other hand, if they still look sick despite being rehydrated, their underlying illness (the cause of the vomiting) is something serious.
Patients who vomit can become dehydrated, & the dehydration itself can cause more vomiting, even if the original cause has gone away. Often an IV seems to cure everything. However, anybody dehydrated who gets better needs to be evaluated the next day, lest vomiting & dehydration return. See Precautionary Tale.
Dehydration or not, our ultimate objective is to figure out why a patient has N/V. Let’s also assume that a basic history & physical examination don’t reveal anything, like they just began a new medication which can cause nausea, or they’re drinking lots of alcohol, or have yellow eyes (jaundice from hepatitis), or a terrible earache. Onward to Diagnosis.
- Chest X-ray, Urinalysis, Complete Blood Count may be indicated
- See our topic Fever
** Abdominal Pain — could an Abdominal Catastrophe be brewing?
- If Pain began before Vomiting, we worry about Appendicitis, Gallbladder disease, Pancreatitis, Diverticulitis, etceteritis. See our topics on Abdominal Pain to guide the diagnostic thought process.
- If Vomiting began first, we don’t worry as much. Vomiting itself can cause pain.
- If the abdomen is very tender, and feels hard-like-a-board when we press on it, we send the patient right to the E.R. (possible Peritonitis, a massive infection).
** Bloody Vomit — something bad in the stomach (worse if the esophagus). We’d call 911, start an IV. BUT…
- “Blood” means at least a handful’s worth. Specks of blood don’t count.
- “Coffee-Ground” vomit (looks like old coffee grounds) is old blood. We treat for a Stomach Ulcer as an outpatient if they’re completely stable, but need to follow them daily to be sure. We’d obtain a complete blood count for the hemoglobin level to be sure they’re not too anemic, and arrange for a gastroenterologist to look in the stomach by endoscopy.
- If we get a phone call from a patient with bloody or “coffee-ground” vomit, we tell them to go to an E.R.
- A patient with Cirrhosis (from alcoholism or other known liver disease) with coffee-ground vomit needs to go to an E.R. — they could be bleeding from the esophagus, which is more dangerous than the stomach.
- For nausea with or without vomiting, we ask if their stools look pure black & tarry (called “melena”). Melena stools are clotted blood; we deal with it as for coffee-ground vomit. But we always ask if the patient was taking iron tablets, Pepto-Bismol®, or multivitamins with Iron, all of which turn stools black
** Immunocompromised — People with weak immune systems are at increased risk for all sorts of terrible infections (see link for examples of immunocompromising conditions). So when they come to see us with a potentially alarming symptom, like new N/V, we take them very seriously. We may well send them to an E.R. for same-day tests as discussed below.
See also Diagram — Gastro-Intestinal Anatomy.
So, let’s assume these above factors are NOT present, and that the patient doesn’t look very ill. Also, assume our exam doesn’t find anything, and that the belly is soft when we press on it. The discussion below follows the clinician’s general thought process when face-to-face with patients who come in with new-onset N/V.
Making a Diagnosis
DAY #1 of Symptoms — We diagnose probable Staphylococcal Food Poisoning due to the common bacteria Staphylococcus aureus (“Staph“). It’s actually due to a toxin, secreted by germs that grew in mayonnaise or similar media, dropped off by a food handler (also occurs from precooked/prepackaged meats). If others from the same house or party are also ill, the diagnosis is clinched.
The Incubation Period (the time it takes enough germs to grow & secrete enough toxin) is up to 8 hours. Treatment? Well, vomiting itself works well — it clears the toxins. Anti-vomiting medicines might relieve symptoms, but might easily prolong them. Antibiotics don’t work at all.
“Gastroenteritis” literally means “infection of stomach and/or bowel.” If there’s only N/V, it’s the stomach. Diarrhea signals bowel involvement.
DAY #2 — Staphylococcal Gastroenteritis will be getting better by now. If symptoms haven’t eased up, Acute Gastroenteritis due to Norovirus or Rotavirus are certainly possibilities, and may start with vomiting alone (no diarrhea yet). I’m cautious about diagnosing viral gastroenteritis in the absence of diarrhea, but it’s possible for up to 48 hrs. of viral illness. We might also order a Urine Pregnancy Test if any chance at all (see link for unlikely cases).
DAY #3 Onward — I’d never diagnose viral gastroenteritis after 48 hours of N/V and no diarrhea. Now’s the time for some sort of basic work-up:
- Urine Pregnancy Test
- Complete Blood Count (general indicator of possible infections, including Sepsis)
- Urinalysis (for Kidney Infection, Diabetic Ketoacidosis)
- Comprehensive Metabolic Panel (for sugar, sodium, calcium, kidney & liver disease)
- Lipase (for Pancreatitis, especially if any upper abdominal pain)
- Erythrocyte Sedimentation Rate (ESR, Sed Rate) [maybe; significant only if very high, which might indicate various causes of inflammation or infection; many clinician’s wouldn’t order this]
The above tests may suggest or diagnose many common causes:
Of course, we may order this work-up on Day #1 or #2 of symptoms, depending on how the patient looks. We’d be more aggressive in the elderly, debilitated, or immuno-compromised. And it may be hard to tell someone who pays for a visit with 2 days of N/V, “come back tomorrow if you’re not better & there’s no diarrhea, & we’ll do some tests.”
We never forget the most important Question to ask all patients all the time:
- “Is the [whatever symptom] getting better, getting worse, or staying the same?” “Getting worse” will generate more tests; “getting better” fewer
While the above tests are pending, we give a high-dose Proton Pump Inhibitor (PPI) (brand names like Prilosec®, Nexium®, Protonix®, etc.), to take twice a day (usual dose is just once). That’s because Gastritis & Stomach Ulcers are common conditions which might cause N/V, even without pain or tenderness. I personally prefer this to anti-nausea medications, because the latter don’t truly treat anything, while PPIs treat actual diseases.
We have the patient return in 1-2 weeks, always making sure we have a contact telephone number lest there be a critical lab result. And of course, we tell them to return earlier if symptoms get worse. If symptoms had been going on and stable for 2 weeks when first seen, we’d tell them to return in 2 weeks.
By a week, if there’s any stomach disease, PPIs will have begun to work. If there’s been absolutely not the slightest decrease in symptoms within a week, we discontinue the medication.
If symptoms have begun to improve, we shouldn’t take ourselves too seriously; maybe whatever condition they had has resolved on its own. At any rate, now we decrease the dose to a more standard one for 1-2 months, or change to another type of stomach medication, an H-2 blocker (brands like Pepcid®, Zantac®, Axid®) & follow.
More importantly, at follow-up we reweigh the patient. Documented proven weight loss requires more investigation — upper endoscopy and maybe an abdominal CT scan. Patients can also weigh themselves at home, best as soon as they get up in the morning, in the same attire each time (naked, same pajamas, etc.), & after they urinate. The accuracy of the scale isn’t so important, since we want to look for weight loss by comparing them on the same scale (but not home scale one day, office scale another).
Nausea / Vomiting that’s Chronic and/or Recurrent
After a month, when N/V can be considered chronic, and all tests are normal, there’s no weight loss, and medicine for stomach acid (like a PPI) doesn’t help, the condition is often psychological. We seek symptoms of Depression, and treat if suggestive. Bulimia (self-provoked intentional vomiting due to obsessions about weight) is more serious, and patients don’t usually admit it. We look for subtle signs, like erosion of tooth enamel, swelling of parotid glands (sides of the cheeks), or calluses on the back of the hand [see link as well]. Adrenal Insufficiency (Addison’s) is highly uncommon (we’d check postural vital signs for major drop in blood pressure upon standing, perhaps order a blood test before 9:00 AM for Cortisol).
We’d probably refer to a gastroenterologist, who might perform endoscopy. Even if normal, it might help reassure the patient. Treatment of psychological nausea is difficult, since long-term use of recommended medications can cause abnormal movements (“extrapyramidal symptoms”), that sometimes become permanent (“tardive dyskinesia”).
Finally, for an obscure syndrome, it seems that chronic heavy marijuana use can cause persistent vomiting. Symptoms tend to last under a week, disappear, and come back. Compulsive bathing / repetitive hot showering was an associated symptom which could serve as a key clue.
See also Nausea / Vomiting for the clinician’s condensed thought-process when face-to-face with a patient.