Death cap mushrooms are thriving from recent summer rains and warmer temperatures, and ACT Health has reiterated warnings to the public in the wake of the three cases yesterday.

One patient presented to the Canberra Hospital and another two presented to Calvary Hospital after eating the mushrooms.

ACT Health couldn't discuss the cases of individual patients, and the severity of their conditions remains unknown.

Death cap mushrooms can cause liver failure and death.

There have been three deaths and 12 reported cases of poisoning associated with death cap mushrooms in the ACT over the past decade.

Acting Chief Health Officer Andrew Pengilley urged Canberrans to think twice before eating mushrooms found in the wild.

''The fact that we've had some people admitted having eaten these mushrooms raises the issue and I think we should just let people know that they need to be extraordinarily careful when collecting wild mushrooms,'' he said.

''As the name would suggest they're quite seriously toxic... the key really is that if people do eat them and they get sick, that they seek treatment very quickly.''

Death caps generally grow around oak trees, making them particularly prevalent in the ACT.

Dr Pengilley said the death caps could be hard to identify.

''Even if you get one death cap mushroom in a whole basket of other mushrooms, that can be enough to cause you serious problems. The best way to be safe is really, quite simply, buy your mushrooms from a grocer.''

Death cap mushrooms can be distinguished by their white gills.

Treatment is more likely to be effective if a patient gets to hospital immediately after eating the mushrooms.

Medical staff can try to flush the mushrooms out of their system and use a variety of drugs to lessen the damage on the liver.

The consumption of death caps can also require a liver transplant.

Typical symptoms include abdominal pain, vomiting and nausea.