Sushi is often seen as a heathy lunch alternative, but doctors have warned that it may be causing parasitic infections, known as anisakiasis.
In one case, doctors found parasite larvae in the gut lining of a 32-year-old man who had recently eaten sushi.
A new study gives sushi eaters a reason to take it easy, reporting there's been an uptick in anisakiasis, a stomach infection caused by a worm that lives in fish, but can easily relocate to your stomach or intestines.
Anisakiasis is caused by eating raw or undercooked fish/seafood infected with nematode parasites of the species Anisakis.
In some cases people can ingest a parasitic worm which attaches itself to the walls of the stomach or gut.
After the larva was removed with a special kind of net, the man's "symptoms cleared up straight away", a team from a Lisbon hospital reported.
It's a common illness in Japan, where people eat lots of raw seafood, but doctors haven't been aware of too many cases in the West until now, and researchers link the spike to the growing popularity of sushi.
An Italian study also advised that medical professionals should suspect the condition should patients complain of severe abdominal pain after eating raw fish, pointing out that "no effective pharmacological treatment is able to kill the larvae once eaten".
The long tube with a camera revealed that the man had a deadly parasitic worm infection, with several worms burrowing into his gut lining.
"Patients can have allergic symptoms like angioedema, urticarial and anaphylaxis", they wrote.
Most of cases of anisakiasis to date had been reported in Japan, however it has been increasingly recognised in Western countries.
Not all sushi is made with raw fish, much of it is cooked. He was also vomiting and had a fever.
According to the CDC, some people will experience a tingling sensation after or while eating raw or undercooked fish or squid, which could actually be the parasite moving in the mouth or throat.
The Food and Drug Administration recommends cooking seafood to an internal temperature of 145 degrees Fahrenheit (63 degrees Celsius) to kill parasites.