The Wall Street star is currently battling throat cancer and has just finished the final stage of his chemotherapy treatment.
His Oscar-winning wife paid tribute to his bravery while hosting the launch the Ryder Cup golf tournament in her native Wales last week (29Sep10), but sparked fears Douglas had taken a turn for the worse when she cut her trip short to head home to New York.
And the actress is so eager not to leave her husband's side while he is ill, she is trying to get out of her work contracts and appearances, including one in China, according to Britain's News of the World.
A source tells the publication, "We are now gravely concerned about Michael's condition. All Catherine cares about is being with him and the kids.
"She had to go to Wales because of a contract. She didn't want to leave her husband, and in the end the separation was too much for her to cope with.
"She's a complete mess as you'd expect. (Her mum) Pat has been saying, 'I've never seen her like this. She's so upset.'
"Catherine is now doing everything possible to get out of having to travel again. She has one more event, in China. We're hoping the organisers will show some sympathy and let her stay with Michael."