Sepsis can be a fatal illness that occurs when the body's response to an infection damages the tissues and organs.

Sepsis Awareness Tasmania chairwoman Sallyann Geale said sepsis is a silent killer because few people know what the life-threatening complication is and what the symptoms are, so often it is not caught until too late.

"At the moment in Australia there are 55,000 cases a year of sepsis and there are 8700 deaths. It's massive," she said.

"People just don't know about it. People need to know about sepsis in the same way they know about heart health, and kidney health, and diabetes, and all those kind of things."

Ms Geale said sepsis is treatable if caught early and the deaths associated with this killer could be avoided if the symptoms were more widely known.

Symptoms of sepsis include rapid breathing and rapid heart rate, confusion, slurred speech or disorientation, fever or shivering, muscle pain, unable to pass urine, and discoloured skin rashes. In children and infants, sepsis can also include convulsion or fits, pale or bluish skin, vomiting, and refusal of feeding.

Ms Geale said if you suspect something is not normal with your infection then you should ask, could it be sepsis?

Cyclist in the event Carolyn Welch, of Riverside, said she hoped that people would see the shirts they were wearing and ask about or google sepsis.

"We are all worried about the virus and other things but not something that kills so many people around the world and it's treatable if you get to it early enough," she said.

World Sepsis Day is Sunday 13. For more information visit: https://www.australiansepsisnetwork.net.au/.