Undercooked Fish: How to Detect and Possible Side Effects

Dish fish

Fish is an important provider of high-quality protein, as well as vitamins and minerals. Nonetheless, if one consumes fish that is not fully cooked, it may result in health issues. It is vital for our wellbeing and safety to be able to identify undercooked fish and comprehend the possible adverse consequences. 

Detecting Undercooked Fish

Culinary expertise significantly aids in determining whether or not fish is thoroughly cooked. However, there are common signs to look out for that require no culinary training. 

  1. Opacity: Fully cooked fish appears opaque throughout. If the fish has any translucent or raw-like sections, it is likely that it is undercooked.
  2. Flaky Texture: Cooked fish should flake easily at the touch of a fork. Lack of this characteristic can indicate the fish is undercooked.
  3. Internal Temperature: Checking internal temperature by inserting an instant-read thermometer into the thickest part of the fish is a surefire way to ensure it’s cooked. The FDA advises that fish should reach an internal temperature of 145°F for safety.
  4. Color and Smell: A visual inspection will show you a vibrant hue rather than a dull color. The smell of the fish should be subtle and fresh. An overly fishy odor is a clear indicator that the fish might be undercooked or spoilt.

Possible Side Effects of Consuming Undercooked Fish

Side EffectDescription
Food PoisoningUndercooked or raw fish may carry bacteria and parasites, which can lead to food poisoning. Symptoms typically include vomit, diarrhea, and stomach cramps
Salmonella InfectionThis bacterial infection can cause fever, diarrhea, and abdominal discomfort
Parasitic InfectionsA parasite known as Anisakis, often found in raw fish, can cause severe illness with symptoms like vomiting, diarrhea, and severe stomach pains.
Viral InfectionsThe risk of Hepatitis A and Norovirus increases with the consumption of undercooked or raw fish. These could lead to severe liver diseases.


Ensuring fish is well-cooked is of paramount importance to avoid the risk of food-borne illnesses. Consumers should be aware of the visual and olfactory indicators of undercooked fish, and should always ensure a safe internal cooking temperature. As the saying goes, ‘Prevention is better than cure,’ it’s always better to be safe than sorry when dealing with undercooked foods, especially fish. 

Reyus Mammadli

As a healthy lifestyle blogger for over 10 years, I couldn't pass up healthy eating and diet reviews. I prefer to write small, understandable articles and guides for visitors, to answer the question clearly and concisely and to give the reader a starting point for further actions to improve their diet and health in general.

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