McLean, VA (written by Ann Oldenburg/USA Today) -- LeAnn Rimes sort of dropped a hint about her plans with a note she posted on her website, recapping her Tuesday milestone birthday:

"30....it feels so different yet no different at all. I had a wonderful day full of peace with my friend's and family. I'm so happy to have arrived here. It's a true time of reflection and healing, exactly what I'm going to do."

She explained that she and husband Eddie Cibrian "went to Nobu for dinner, sat by the water, shared sake, sushi, cake and several happy tears." He gave her "the greatest new camera to capture the next decade of memories with."

And now comes the news that Rimes has entered a treatment center to address emotional issues.

"LeAnn has voluntarily entered a 30 day in-patient treatment facility to cope with anxiety and stress," her rep Marcel Pariseau tells People.com, who says the singer checked in to a center on Wednesday. Pariseau says she is not seeking treatment for an eating disorder or substance abuse.

"This is just a time for me to emotionally check out for a second and take care of myself and come back in 30 days as the best 30-year-old woman I can be," Rimes tells People. Husband Eddie says he will be "with her every step of the way."