The official Twitter account for the ITV show told its 107,000 followers: “Out @reallorrraine is poorly today so @kategarraway is stepping in, thanks Kate! #GetWellSoonLorraine.”
Speaking ahead of the show to Piers Morgan and Susanna Reid, Kate joked: “How exciting! I was still in bed 20 minutes ago.
“I have absolutely no idea what is in the show but shall we find out together?”
Following the news that the 50-year-old would be stepping in for Lorraine, viewers took to Twitter to express their delight at seeing Kate on the show.
“#lorraine Great to see Kate presenting the show today,” one viewer shared.
Another added: “Great news Kate Garraway is hosting #lorraine today now it’s worth watching.”
A third continued: “Hello Kate, what a nice surprise.”
“Get well soon @reallorraine. Good morning @Kategarraway,” someone else wrote.
Kate was joined by Greg James, who opened up on his recent challenge to raise awareness about mental health.
Greg had to cut his challenge to climb Snowdon, Scafell Pike and Ben Nevis short due to the bad weather last week.
Later, Debbie McGee opened up to the host about her sleeping issues for the Lorraine Sleep Revolution campaign.
Debbie explained: “I’ve been really busy working seven days a week for just over six months and now I just feel like my body is racing.
“I can’t get off to sleep and if I do drop off I only seep for three or four hours I can’t calm down.”
Lorraine airs weekdays on ITV at 8.30am.