Symptoms may include diarrhea, vomiting, numbness, itchiness, sensitivity to hot and cold, dizziness, and weakness.

[2] They are originally made by a small marine organism, Gambierdiscus toxicus, that grows on and around coral reefs in tropical and subtropical waters.

[3] The fish most often implicated include barracuda, grouper, moray eel, amberjack, sea bass, and sturgeon.

[2] In 2017, the United States Centers for Disease Control (CDC) estimated that around 50,000 cases occur globally each year.

[13] Diarrhea and facial rashes have been reported in breastfed infants of poisoned mothers, suggesting that ciguatera toxins migrate into breast milk.

[16] Gambierdiscus toxicus is the primary dinoflagellate responsible for the production of a number of similar polyether toxins, including ciguatoxin, maitotoxin and possibly palytoxin.

There is some evidence that calcium channel blockers like nifedipine and verapamil are effective in treating some of the symptoms that remain after the initial sickness passes, such as poor circulation and shooting pains through the chest.

[1] The current estimated global incidence annually is 20,000 to 50,000 people, though a large number of cases are believed to go unreported.

[43] Researchers suggest that ciguatera outbreaks caused by warm climatic conditions in part propelled the migratory voyages of Polynesians between 1000 and 1400 CE.

[44][45] In Northern Australia, where ciguatera is a common problem, two different folk science methods are widely believed to detect whether fish harbor significant ciguatoxin.

On Grand Cayman and other islands the locals will test barracuda by placing a piece of the fish on the ground and allowing ants to crawl on it.

[citation needed] In Dominican Republic, another common belief is that during months whose names do not include the letter "R" (May through August), it is not recommended to eat certain kinds of fish, because they are more likely to be infected by the ciguatera toxin.

[46] Leaves of Heliotropium foertherianum (Boraginaceae) – also known as octopus bush – are used in many Pacific islands as a traditional medicine to treat ciguatera fish poisoning.

Senescent octopus bush leaves contain rosmarinic acid and derivatives, which are known for their antiviral, antibacterial, antioxidant, and anti-inflammatory properties.

The most common old-time remedy involves bed rest subsequent to a guanabana juice enema.

[citation needed] In Puerto Rico, natives drink a tea made from mangrove buttons, purportedly high in B vitamins, to flush the toxic symptoms from the system.

Other folk treatments range from directly porting and bleeding the gastrointestinal tract to "cleansing" the diseased with a dove during a Santería ritual.