But his wife Patti reassured people the TV legend was fine when she posted a photo of him masked up in a hospital bed.
“Bert’s been in hospital, all good,” she wrote alongside the image.
“He’s got a lot of living to do.”
Mrs Newton did not reveal why her husband was in hospital but he is reportedly undergoing tests.
Last year he sparked health fears as he clutched his stomach while leaving a Melbourne hospital with Patti.
Newton has battled several health issues in the past, and spent more than a week in hospital for pneumonia in 2011.
He had caught a viral pneumonia from his granddaughter, Eva.
The year after he faced a six-month recovery period after being released from hospital following quadruple bypass surgery.
At the time he praised Patti’s strength.
“When the pressure is on she holds up like a beauty,” he said.
The couple’s famous friends have flooded Mrs Newton’s post with their well-wishes.
“Get well soon lovely man!!” former Miss Universe Australia Erin Holland wrote. “He’s got the best care in you Patti.”
“Go Bert! Strong as an ox you are. Sending love,” Olympic swimmer Leisel Jones said.
Newton recently became a grandfather for the sixth time after the birth of grandson, Alby, who was named after him.
“Graham (Kennedy) and Don (Lane) called him Alby,” Lauren said.
“Dad burst into tears when mum (Patti Newton) told him Alby’s name and that he had another grandson.
“To have such a long, drawn out, difficult time (pregnancy) and then to have him born and be a boy and be healthy and beautiful and to name him Alby after dad, I just think there could not be a more perfect way for Matt and I to complete our family.”
Lauren spent 80 days in hospital leading up to his arrival after complications put both her and Alby at risk, and he was born seven weeks premature.
Lauren and her husband, former Olympic swimmer Matt Welsh have five other children, Sam, 12, Eva, 11, Lola, 7, Monty, 4, and Perla, 1.