(also known as food-borne illness) occurs when you eat or drink something that contains harmful germs (bacteria, viruses or parasites). Sometimes bacteria produce a toxin in food that causes the problem.
There are two ways to get food poisoning from eating fish: First way is when you eat a reef fish (any fish living in warm tropical water) that has eaten a certain poisonous food. This poison does not go away when the fish is cooked or frozen.
The second way is caused by histamine in fish. A substance called histamine builds up in some fish when they get too warm after they are caught. Histamine is a chemical that serves as a kind of alarm to let your immune system know that an infection is attacking part of the body. If you eat a fish that was not properly cooked after it was caught, you may react to the histamine that is released into your body.
Signs that you may have a more serious case of food poisoning that requires medical attention include:
vomiting that lasts for more than two days
not being able to keep liquids down for more than a day
diarrhea that lasts for more than three days or is bloody
It's important that you do not become dehydrated because it will make you feel worse and lengthen your recovery. Try to drink as much water as you can, even if you can only sip it, particularly every time you pass diarrhoea.
In urgent cases of fish poisoning, it is best to seek hospital care or consult a doctor. The medical experts will perform diagnostic tests and try to expel the poison from the body by providing various treatments. If your symptoms are mild and can be controlled, then you can use home remedies. Such symptoms can include mild vomiting and diarrhea. Fish poisoning can also make the whole body itch. This includes the head.