About Fish Poisoning

There are different types of fish poisoning that can be fatal for those affected. While fish poisoning caused by toxins, for example, can be very dangerous, bacterial fish poisoning is usually more harmless.

What is fish poisoning?

According to ESHAOXING.INFO, fish poisoning is a classic food poisoning caused by eating overlaid or infected fish. In most cases it is bacterial poisoning from contaminated fish.

Various pathogens can be considered in this regard. Viruses and toxins are also among the risk causes. Fish poisoning caused by toxins is fatal in some cases.

Often, however, fish poisoning only causes relatively harmless symptoms that resemble those of a normal gastrointestinal flu.


The cause of fish poisoning usually lies in improper storage of the fish for too long. This is particularly true of bacterial fish poisoning. This type of poisoning is harmless in and of itself.

In addition, the fish can also be infected with viruses. Furthermore, special types of fish cause dangerous poisoning, especially if they are improperly prepared, for example the Japanese puffer fish, which contains a toxin. In the puffer fish, the poison is mainly in the organs. The poisoning occurs when traces of it get into the ready-to-eat muscle meat.

The so-called ciguatera poisoning is also very much feared. The trigger is a toxin that is particularly found in fish caught in the Pacific Ocean. If the animals are infected with the toxin, the poison cannot be rendered harmless by heating.

Finally, botulinum toxins as a result of incorrect storage in the event of fish poisoning come into consideration.

Symptoms, ailments & signs

As with food poisoning in general, the symptoms of fish poisoning primarily depend on what made the fish inedible. Fish poisoning caused by bacterial contamination from improper storage or storage for too long mainly causes short-term but severe gastrointestinal complaints such as nausea, diarrhea, abdominal pain and vomiting. The complaints caused by spoiled fish often appear a few hours after consumption and subside after a short time.

In the case of fish poisoning caused by other toxins, various other symptoms and complaints can occur depending on the type of poison. These can also be dangerous in different ways. In addition to vomiting and diarrhea, other longer-lasting symptoms such as itching, headache, pain in the limbs and abnormal sensations can occur here. Some symptoms may persist or recur for months after the actual poisoning.

Certain types of toxins can cause symptoms similar to allergic shock, such as a sudden rash or swelling and redness of the face within minutes of ingestion. Other toxins, including, for example, the poison of the puffer fish, can lead to severe symptoms of paralysis, which can lead to potentially fatal respiratory paralysis.


In most cases, fish poisoning is diagnosed on the basis of anamnesis. This means that you can assume that you are suffering from fish poisoning if unpleasant symptoms in the stomach and intestines, such as diarrhea, vomiting and stomach pain, become noticeable shortly after eating the fish meal.

In most cases this is bacterial fish poisoning. If the cause is unclear, it is possible to examine the feces or the remains of the eaten fish in the laboratory for potential pathogens. Fish poisoning can also be caused by viruses. As a rule, these are just as “harmless” as most bacteria.

In the event of a high fever and general weakness, the doctor can also identify the pathogen on the basis of a blood test. Botulinum fish poisoning can be recognized by the fact that a large number of people fall ill, especially after consuming infected canned fish. Botulinum toxins can be detected in the blood and in the stool and are therefore an unmistakable sign of fish poisoning.


In the worst case, fish poisoning can lead to death. Whether or not serious complications arise from fish poisoning depends heavily on whether it is caused by toxins or bacterial poisoning. In most cases, bacterial poisoning proceeds without major complications.

In most cases, fish poisoning results in severe abdominal pain, diarrhea, vomiting, and fever. These symptoms can be accompanied by nausea and tiredness, so that the patient’s everyday life is severely restricted. In most cases, it takes a few days for fish poisoning to be completely overcome.

Bacterial poisoning is relatively harmless and does not require steep treatment. However, if poisoning by toxins occurs, treatment by a doctor is necessary. In doing so, the body loses many minerals and vitamins and is weakened as a result.

Fish poisoning can also negatively affect and damage the central nervous system. Treatment is carried out either with ordinary medication or by administering an antidote. There are no particular complications if the treatment takes place early.

When should you go to the doctor?

Fish poisoning is always a serious condition. Immediate medical treatment is required. Food poisoning from bacterially contaminated or spoiled marine animals can cost those affected their lives if they are not treated immediately. If symptoms of fish poisoning occur after eating mussels, fish or crustaceans, seek medical advice immediately.

Real fish poisoning is an intoxication. This must be differentiated from gastrointestinal complaints that occur after eating bacterially contaminated fish dishes. Both can lead to diarrhea. The real fish poisoning, however, comes from the spoiled parts of cooked seafood. It is therefore also far more dangerous. However, diarrhea-related dehydration can occur with both diseases.

The symptoms after eating fish dishes or mussels that have been contaminated with bacteria or spoiled are initially identical. But the toxins from real fish poisoning can wreak havoc on the body. If left untreated, they can lead to impaired vision, numbness of the limbs, or fatal respiratory paralysis. The symptoms of poisoning are often so severe that those affected suffer from after-effects for weeks after the actual poisoning.

People in Japan risk a special kind of fish poisoning with the consumption of puffer fish. In the event of improper preparation, those affected die from tetrodotoxin poisoning. This is caused by improperly removed innards of the puffer fish.

Treatment & Therapy

While a simple bacterial or virus-related fish poisoning does not require any special treatment, but mostly disappears by itself after a few days, the course of fish poisoning, which is caused by various toxins, is often much more difficult.

Since severe diarrhea is often associated with a loss of water and minerals, an infusion is necessary in particularly severe cases to stabilize the fluid and electrolyte balance. Antipyretic drugs such as paracetamol help with fever and pain. Ibuprofen is unsuitable, however, as the agent only puts more strain on the gastrointestinal tract.

When treating botulinum toxin fish poisoning, the doctor uses an antidote. There is no time to lose because such poisoning is often fatal. Treatment is usually carried out in the hospital and, in this regard, in the intensive care unit, since the antidote is introduced into the veins.

Hospitalization is also necessary in the case of puffer fish poisoning. In the case of ciguatera poisoning, the stomach is pumped out. Then the sick person is given an alcohol-sugar solution to stimulate urination so that the poison can get out of the body. When ciguatera fish poisoning, it can also lead to complications, as the central nervous system is affected.

Outlook & forecast

The prognosis for fish poisoning depends heavily on the type of toxin that enters the body. For example, most bacterial fish poisoning can be considered harmless. The symptoms usually pass by themselves within a few days. This is often the case even if left untreated.

The situation is different with the poison of the puffer fish, for example. The tetrodotoxin in it can kill a person if not interfered with. It is believed that a person who is still alive 24 hours after ingesting the poison has a very good chance of survival. The faster medical treatment is provided, the better the chances of survival.

If botulinum toxins were found in the fish, if left untreated, a particularly severe course of the disease can occur, which is fatal in a good two thirds of all cases. Even treated, such poisoning can be fatal in a tenth of all cases.

Ciguatera fish poisoning is treatable, but has single-digit mortality rates. In addition, it is possible that those affected continue to suffer from neurological symptoms months later. The complaints in the gastrointestinal tract and circulatory problems, however, pass within a few weeks.


Botulin toxin fish poisoning is usually caused by spoiled canned fish. That is why you should stay away from deformed and especially bloated cans.

One can avoid bacterial fish poisoning by only preparing really fresh, odorless fish. In addition, as a precaution, the consumption of puffer fish should be avoided. Fish poisoning by Ciguatera pathogens occurs particularly in fish caught shortly after a seaquake in the Pacific Ocean.


Follow-up care for fish poisoning is primarily aimed at preventing the typical symptoms from recurring. This is done through preventive measures. Compliance with storage standards and the correct preparation of a fish are crucial. Toxins must never get into the human bloodstream.

After a finally treated fish poisoning, the body does not build up immunity. Rather, the patient can fall ill again and again without observing the preventive measures described. The attending physician then conducts a symptom-related examination. A blood sample provides final clarity. To avoid complications, you should definitely consult a doctor if you suspect it. In severe cases, there is a risk of fatal symptoms of paralysis.

In some cases, such as puffer fish poisoning, longer treatment is necessary until the patient can continue to live without symptoms. The primary goal of aftercare is to get the toxin out of the body. If further impairments have occurred, their therapy is added. People of advanced age are considered to be at risk. Due to their age, their organism recovers much more slowly. Blood tests are therefore carried out on them from time to time.

You can do that yourself

Classic fish poisoning, i.e. poisoning caused by eating fish, is typically caused by incorrectly storing freshly caught fish for too long. Most of the time it is bacterial poisoning, which usually does not require medical treatment.

The most important self-help measure is to maintain an electrolyte balance because vomiting and diarrhea, as well as profuse sweating in the event of a fever, excrete a lot of minerals that need to be replaced.

A second – by far more dangerous – variant of fish poisoning is poisoning by toxins that the particular fish is known to carry. Poisoning occurs when the fish was not prepared in such a way that the toxin could not get into the part of the fish to be eaten. One type of fish that contains a highly toxic nerve toxin is the Japanese puffer fish, which requires special preparation so that the toxin is not consumed.

If fish poisoning with botulinum toxin or another neurotoxin does occur, it is an acute emergency that requires immediate treatment in a clinic, which ideally also has an antidote that can be administered intravenously. Because of the acute emergency, self-help measures or adjustments in everyday life are unnecessary.

A third type of fish poisoning is the so-called ciguatera poisoning, which occurs through the consumption of normally non-poisonous predatory fish under special conditions via the food chain. Here, too, are acute emergencies that require immediate clinical treatment, because z. B. There is a risk of respiratory failure.

fish poisoning