Gov.-Gen. Michaelle Jean is back at work after recently being diagnosed with a thyroid condition that triggered extreme fatigue.

Jean, 49, was diagnosed last Thursday with a thyroid malfunction. The Thyroid Foundation of Canada says the condition can, in extreme cases, cause people such fatigue that they fall asleep in mid-sentence.

Spokeswoman Isabelle Serrurier says a five-day reduced workload has helped and doctors are still monitoring the Governor General.

She was back at her post on Wednesday, planting a tree and meeting with Hungarian President Laszlo Solyom, who is in Ottawa for a state visit, and delivering a speech about Canada's ties with his country.

The Governor General's energy levels appear to have plummeted of late. She failed to appear for the opening of the National Arts Centre's Quebec Scene on Friday, and also cancelled her appearance Sunday at the Lieutenant Governors and Commissioners Conference in Regina.

In an ironic twist, Jean is the Thyroid Foundation of Canada's honorary patron, a title her predecessor, Adrienne Clarkson, had not accepted.

Symptoms of a thyroid problem include lethargy, mood swings, weight gain or loss, and depression.

It is estimated that 200 million people in the world have some form of thyroid disease, according to the Thyroid Foundation of Canada.

Recent studies indicate that one in three Canadians, more than 10 million people, suffer from a thyroid disorder. Of those, as many as half are undiagnosed, the foundation says on its website.

David Dyment, a former advisor to Clarkson, noted earlier this week that the work of a governor general can be exhausting.

"It's a very full schedule with a number of different dimensions," he told CTV Newsnet.

"The Governor General has to really be aware of what's going on in the world around her. And I think people don't realize that she's in charge of an organization of over 200 people. So you're managing 200 people, you have senior people to help you, but still, a lot of the things end up on your desk."