Kate Major -- Missing From Rehab

Kate Major went missing last night after she apparently wandered off from the hospital ... TMZ has learned

According to her rep, Major was transferred from rehab in Boca Raton, FL to a nearby hospital after suffering a seizure. The rep says Major left the hospital on her own and no one knows where she went.

We're told Major has no money, no phone, no credit cards and only the clothes on her back.