The mother-of-three, 35, was absent on today's show while she tended to Chester, one, who was treated at the Chelsea and Westminster Hospital in London over the weekend and today.
Chester needed stitches after falling over, but is thankfully fine.
Holly's co-host Phillip Schofield explained the situation today, saying: "Chester, her youngest son, yesterday fell over and banged his head, and he's got a very nasty cut on his head. They dressed it overnight, and today he has to go back into hospital where they're going to put stitches in it, so that's where Holly is. But he's absolutely fine and he was playing after it."
Holly - who was replaced by Ruth Langsford for today's show - later thanked viewers for their well wishes and assured them little Chester is doing okay. She also praised the hospital staff for their help.
Alongside a photo of Chester in a hospital gown – his face turned away from the camera – she wrote: Thank you for all the lovely kind messages... Chester is just fine and was definitely the bravest out of all of us...
"He received brilliant care from everyone at the #Chelseaandwestminster hospital, makes you realise again how lucky we are to have such a wonderful #nhs. Also huge thanks to @ruthlangsford for coming to the rescue and@itvthismorning for being so understanding as always!!!"
Holly and husband Dan Baldwin also have son Harry, seven, and daughter Belle, five.