Catherina Zeta-Jones has opened up about her battle with bipolar II disorder after her husband Michael Douglas was diagnosed with cancer back in 2010.

The Welsh actress spoke with Telegraph's Stella magazine and explained her disorder, for which she went into a health care facility for in May for treatment. "Bipolar is something I have been dealing with for a long time," she said.

At the time the actress checked in, her publicist released a statement saying: "Catherine has proactively checked into a healthcare facility. Previously Catherine has said that she is committed to periodic care in order to manage her health in an optimum manner."

She explained that she was "sideswept" by Douglas' cancer, saying she was stressed out and not sleeping. "When Michael was diagnosed with cancer I really thought, 'You are going to have to wipe me off the floor,'" she said. "When you get sideswiped like that [by Douglas' cancer] it's an obvious trigger for your balance to be a little bit off, not sleeping, worry, stress. It's a classic trigger."

She recalled the time he was receiving chemotherapy. "I wasn't as strong as I thought I could have been. I look back and I can't believe the strength he had."

The 43-year-old had visited a treatment center. In 2011, she was treated for five days to manage her disorder.

Zeta-Jones said that she spends a lot of time together with Douglas but also has a place in her home where she can be alone. "We spend a hell of a lot of time together, so we are careful to maintain our space. "We recently had an extension built, to house a closet. It's like the Tardis - I go in there and never come out."

The actress married Douglas in 13 years ago and the two pair have two children together. She won an Academy Award in 2002 for the musical "Chicago"

Bipolar II is a milder form of the disorder and can be treated with medication or therapy.

See a video report of Catherine Zeta-Jones' bipolar disorder.