What Is Botulism?

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Botulism is a very serious, potentially fatal condition that occurs as a result of a toxin that is produced by a bacteria called Clostridium botulinum. Botulism leads to muscle paralysis, which usually begins in the face, causing symptoms like a droopy eyelid and/or slurred speech. The paralysis may then spread downward, affecting the muscles in your neck, chest, arms, and legs.

 Verywell / Gary Ferster

Botulism Symptoms 

The bacteria that cause botulism produce botulinum toxin, a neurotoxin that binds to the tiny space between a nerve and a muscle, preventing the nerve from sending a message to the corresponding muscle. When a nerve cannot send a message to direct a muscle to move, the muscle becomes paralyzed.

Botulism classically first causes paralysis of the facial muscles. This may cause one or more of the following:

  • Droopy eyelids
  • Blurred or double vision
  • Difficulty speaking or slurred speech
  • Trouble swallowing
  • Dry mouth

Anyone can develop botulism, including babies and young children. Instead of the above symptoms, though, infants with botulism may:

  • Appear "floppy" and lethargic
  • Have a weak cry
  • Be constipated
  • Feed poorly

As the bacteria can produce large amounts of botulinum toxin, it can end up spreading throughout the body, paralyzing many muscles at a time.

If you experience or observe the signs of botulism, you should seek medical attention immediately. The toxin released from the infectious bacteria that cause botulism can rapidly cause dangerous paralysis, after which the condition is much more problematic and difficult to recover from.

Types and Causes of Botulism

Botulism is most often caused by Clostridium botulinum, but may also be caused by Clostridium butyricum and Clostridium baratii.

There are five types of syndromes related to botulism. They all cause similar symptoms related to muscle paralysis, but their origins differ.

Food-Borne Botulism

This is the most common type of botulism. Canned foods, such as fruit, vegetables, and fish, can be contaminated with preformed botulinum toxin.

In general, canned foods that are prepared at home without the use of safe processing methods are at the highest risk. But there are also outbreaks of botulism related to professionally and industrially canned foods, though these outbreaks are few and far between.

Infant Botulism

Infant botulism occurs when the spores of the bacteria get into a baby's intestines, grow, and eventually produce the neurotoxin.

Adult Intestinal Toxemia Botulism

Adult intestinal toxemia botulism is very rare and occurs when, as with infants, the spores of Clostridium botulinum get into a person's intestines and then grow and make the toxin.

Iatrogenic Botulism

Sometimes botulinum toxin (Botox) is deliberately used for cosmetic injections to temporarily prevent the appearance of wrinkles, prevent migraine headaches, or relieve muscle stiffness.

While it is not common, injections of botulinum toxin for medical or cosmetic reasons can cause unwanted paralysis of eye movement or facial muscles, which is usually temporary.

Wound Botulism

Wound botulism is a very rare botulism syndrome. Wounds that become infected with Clostridium botulinum are generally associated with injection drug use, especially the injection of black-tar heroin (a sticky, dark-colored type of heroin) into the skin or muscle.

Surgical incisions, abrasions, lacerations, open fractures, or sinusitis from using cocaine intranasally (through the nose) can also increase the risk of this type of infection.


Botulism is not a common medical condition, but if you experience face, eye, or mouth weakness, your medical team will do a thorough medical history and physical examination to determine the cause. Botulism may be considered alongside other, more likely diagnoses.

Medical History and Physical Examination

During a person's evaluation for potential botulism, a doctor will look for the presence of three criteria, based on data from the United States National Botulism Surveillance Database:

  • Lack of fever
  • A symptom of cranial neuropathy (such as blurred or double vision or difficulty speaking)
  • A sign of cranial neuropathy (such as drooping of the upper eyelid or facial paralysis)

In infants, a doctor will look for a sudden onset of weak suck, drooping eyelid, lack of activity, and constipation.

In order to assess for potential botulism exposures, various questions may be asked, such as:

  • Has your infant been exposed to honey?
  • Do you can foods on your own at home?
  • Do you have a history of trauma or injection drug use?
  • Have you recently undergone Botox injections for cosmetic reasons?

Specialized Tests

Often times, special tests are required to make a diagnosis of botulism, considering the symptoms can mimic several other neurological conditions, such as:

Some of the tests that may be ordered to sort out the correct diagnosis include:

Laboratory Tests

Various laboratory tests are used to confirm a diagnosis of botulism. These tests evaluate blood, stool, wounds, or food sources to either look for the presence of the toxin or the bacteria.

The downside of tests for botulism is that the results may take days to come back. This is why, if it is suspected, treatment must be started before the diagnosis is confirmed.


The treatment of botulism starts with immediate hospitalization and antitoxin administration.


Hospitalization and close monitoring, usually in an intensive care unit (ICU), is the mainstay of treatment of people with botulism. Some patients require intubation with mechanical ventilation (a breathing machine) for symptoms or signs of respiratory failure from paralysis of the breathing muscles.


In addition to hospitalization with close monitoring, patients with botulism will be given an antitoxin drug. The antitoxin works by binding to and preventing the botulinum toxin from paralyzing the muscles. An antibiotic, most commonly penicillin, is also given to kill the Clostridium bacteria.


Surgical wound debridement, in which the wound is vigorously cleaned out to remove the infected tissue, in addition to antibiotics and antitoxin, is reserved for the treatment of wound botulism.


Since the majority of cases of botulism occur as a result of food ingestion, learning proper food handling and preparation is your best bet for prevention.

Proper Food Handling and Preparation

Bacteria can grow when canned food is exposed to oxygen through a dent, slit, or a small hole in the can. As such, it's best to throw away any damaged cans.

In addition, if you have a can of food that shows signs of liquid bubbling or a bad smell, it's safest to discard it.

If you practice home canning, be sure to follow pressure cooker/canner instructions precisely to destroy spores produced by Clostridium botulinum. Boiling any home-canned foods for at least 10 minutes is also important, considering the botulin toxin is very heat labile.

Avoiding Honey in Infants

Avoid giving honey to babies less than a year old to help prevent infant botulism. Their digestive systems are not developed enough to destroy the bacteria before it can cause harmful effects.

Practice Proper Wound Care

Be sure to obtain prompt treatment of all wounds. Likewise, avoid injection drug use to protect yourself from related skin damage.

A Word From Verywell

With the discovery of a botulinum antitoxin and the advances in medical education and monitoring about this condition, less than five out of every 100 people with botulism die. That said, botulism still remains a very serious illness that requires immediate treatment.

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8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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