Is Blue Vomit or Bile Serious? Causes & Treatment

Key takeaways:

• Blue vomit is a rare, but potentially life-threatening symptom.
• Chemical ingestion and poisoning are the most common causes of blue vomit.
• A full history, including your occupation and diet, will be an important part of diagnosing the cause of your blue vomit.

Observing bluish-colored vomit can be alarming for anyone who experiences it. It is a rare condition with a few different causes – from benign discoloration (not serious) to accidental poisoning and chemical ingestion (life-threatening).

In this article, we’ll explore what blue vomit is, its causes, how it’s diagnosed, and how it can be managed and treated.

What is blue-colored vomit or bile?

If you feel nauseous, you may have an overwhelming urge to throw up. That isn’t necessarily cause for concern – but seeing that your vomit is a bluish color is.

Blue-colored vomit or bile typically results from specific substances in the stomach or bile duct. In benign cases, blue vomit may be caused by the ingestion of foods and drinks containing high amounts of blue food dyes – but those cases are rare. A much more likely cause is poisoning.

When throwing up blue vomit or bile may be serious

Without exception, blue vomit should always be taken seriously. If you have been vomiting and notice that it is bluish-colored, immediately get medical attention.

Whenever someone seeks medical help for blue-colored vomit, the likely suspect is chemical poisoning.

The most common causes of blue vomit or bile

The most typical poisonous substances associated with blue vomit are copper sulfate, boric acid, and a chemical known as paraquat. Following is information about each, along with possible dietary causes.

Copper sulfate poisoning

A combination of copper and sulfur, copper sulfate is a toxic chemical that kills algae, bacteria, and fungi.

Poisoning with copper sulfate can lead to blue-colored vomit as well as other symptoms such as abdominal pain, diarrhea, muscle cramps and spasms, and seizures.

This type of poisoning may affect individuals who work with (or have exposure to) products that contain copper. If you seek medical help for blue vomit, be sure to let your healthcare provider know about any possible workplace exposures to chemicals.

Boric acid ingestion

Boric acid is an especially dangerous poison. It can be found in a variety of products including antiseptics and astringents, some paints, pesticides, photography chemicals, and enamels and glazes.

The most common symptoms of boric acid poisoning are blue-green vomit, diarrhea, and a bright red rash on the skin. Other possible symptoms include fever, headache, drowsiness, seizures, blisters, and decreased urine output.

Paraquat ingestion

Paraquat is a toxic chemical found in herbicides and used for weed and grass control. Because it is highly poisonous, the U.S. Environmental Protection Agency classifies paraquat as a “restricted-use” substance.

That means only those with commercial licenses can access and use the chemical. Paraquat comes in liquid form, in various strengths, and contains a blue dye to keep it from being confused with beverages. If ingested, it can lead to blue-colored vomiting. It can also cause abdominal pain, diarrhea, and low blood pressure.

Dietary causes

Blue food dye is an ingredient in some candies, juices, and ice pops. If you eat foods colored with blue food dye and then vomit, you may notice that your vomit is bluish-colored.

Although this in itself is not an emergency, always take blue-colored vomit seriously and see your healthcare provider.

Causes of blue vomit or bile based on appearance or other symptoms

Blue-colored vomit can alert your doctor that something serious may be going on. But to narrow down the potential cause, be sure to look beyond the color and examine other aspects of the vomit.

Blue and green vomit or bile

Blue and green vomit can be caused by the ingestion of several different poisonous chemicals. Uniformly blue vomit due to chemical poisoning is known as the Andouard sign.

This symptom may also be due to dietary intake of foods and drinks that contain blue food dyes. If the vomit is more green in color, it may be due to gastroenteritis (inflammation in the stomach) or bile reflux.

Blue, chunky vomit

Vomit that is chunky in texture may simply be from partially digested foods. In more serious cases, however, it may be due to coagulated or clotted blood.

If you ingest a substance such as boric acid that can lead to holes or perforations in the gastrointestinal tract, internal bleeding is possible. Together, the boric acid and clotted blood may be expelled in the form of blue, chunky vomit.

Blue specks or spots in vomit or bile

If you vomit and see blue specks or spots in it, the cause is most likely partially digested food that contains blue food dye.

Contact your healthcare provider, however, and let him/her know if you’re experiencing any additional symptoms.

Blue or blue-green vomit or bile during pregnancy

The causes of blue or blue-green vomit in pregnancy are the same as those discussed previously.

Possible chemical ingestion and poisoning should always be considered, so seek medical attention promptly. Also, talk to your doctor about your diet over the past one to four days.

Vomiting blue on an empty stomach

If you’re throwing up blue vomit and haven’t eaten anything, this could be a danger sign. With nothing in your stomach, it’s unlikely that the blue vomit is due to foods colored with blue dyes – and instead, could be chemical poisoning.

Vomiting blue after drinking alcohol

Some types of alcohol and alcohol mixers contain blue food dye. If you’re throwing up after consuming one or more alcoholic beverages containing blue dye, this may be what caused the blue vomit – but don’t assume.

It’s important to remember that certain chemicals (such as paraquat) come in liquid form and can be mixed into drinks. Chemical poisoning should always be considered with blue vomit, even when occurring after drinking alcohol.

Read our guide on different types of vomit and its colors for more.

Diagnosing the causes of blue vomit or bile

Diagnosing the cause of blue vomit or bile will rely heavily on a thorough history. Be sure to let your healthcare provider know about any possible chemical exposures, either at work or at home. Reviewing additional symptoms you may be experiencing can also help your provider determine what’s causing your blue vomit.

In some cases, blood tests and urine tests can be used to identify whether chemical poisoning is the cause of your blue vomit. Your healthcare provider may also consult with poison control for additional help in the workup.

Common treatment options for blue vomit or bile

Poison control can help identify what chemical may be causing your blue vomit – but that’s not all. The professionals who work in poison control can also help with treatment recommendations based on the specific chemical.

Medication

Activated charcoal may be used to prevent further absorption of chemicals such as paraquat, but this is not recommended if the ingested substance contains acid. It will only be used when the source of the blue vomit has been identified.

In that case, you may be given a specific antidote while in the hospital. Other medications such as acid-reducing medications, anti-nausea medications, and medications that coat and protect the stomach may be used on a case-by-case basis.

Surgery

If your blue-colored vomit is due to the ingestion of an acid-containing chemical, you may need surgery.

Swallowing large amounts of substances that contain acids can cause damage and burns to the stomach and esophagus and may even cause holes (perforations) in them. Perforations always require corrective surgical procedures.

Decontamination

The most common route of poisoning is through oral ingestion. However, some chemicals can be absorbed through the skin (especially if you have any open wounds), and may also be inhaled.

Many healthcare facilities and hospitals have spaces that specialize in decontaminating you. This will protect you from further exposure to the chemical that’s causing your symptoms.

Supportive measures

Supportive care such as IV fluids and rest are always recommended after episodes of vomiting.

Chemicals such as copper sulfate, boric acid, and paraquat can have a serious impact on your organs. In the most severe cases, mechanical ventilation will be used to help your body with its normal functioning while it clears the poisonous substances from your system.

Questions to ask your doctor about blue vomit or bile

• What could be causing this blue-colored vomit?
• Is this a sign of a serious underlying medical condition?
• What tests will I need to diagnose the cause of the blue-colored vomit?
• What treatments are used to address this?

Frequently asked questions: blue vomit or bile

Since blue vomit is not a common symptom, you’ll likely still have some questions. Here are the answers to some of the more frequently asked questions about blue vomit or bile.

What can you eat or drink after throwing up blue vomit or bile?

What you can eat or drink after throwing up blue vomit or bile will depend on the cause. If the bluish-colored vomit is due to blue-colored foods, you’ll want to start with a clear liquid diet and advance as you can tolerate solid foods.

If your blue-colored vomit or bile is due to chemical poisoning, your healthcare provider will give you specific dietary guidelines. These will be based on the identified cause as well as the treatment prescribed to you.

Read our guide on what to eat or drink after vomiting for more.

Is blue vomit a sign of food poisoning?

Probably not – blue vomit is most likely to be caused by chemical poisoning rather than food poisoning. In some cases, though, it’s possible to have blue vomit from food poisoning. That might occur if you ingest a blue-colored food that makes you sick and causes you to vomit.

Managing blue vomit

Even with potentially benign causes for blue vomit, such as consumption of foods colored with blue dye, always take this symptom seriously. Many cases of blue vomit are due to chemical poisoning, which can be fatal if not addressed as soon as possible. If you ever find yourself experiencing this strange and rare symptom, do not hesitate! Visit the ER or consult your healthcare provider immediately.

General Medicine follows a strict editorial process, including using real experts to write our articles, vetted primary sources, fact-checking, a secondary medical review, and updates as necessary. This article was medically reviewed and fact checked by Dr. Lane Thaut, DO.

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