Ratathini Hongwichitpreech apparently had a taxi drive up from Bangkok to Udon Thani to take her to Samut Prakan province.
The leader of the Samut Prakan community she lived in tracked her down on Thursday. The patient said she left the hospital because she wanted to be with her husband.
Ratathini will complete her treatment at a hospital in Samut Prakan and will face legal action once she recovers.
The Kumphawapi Hospital in Udon Thani has also filed an official complaint against the patient for escaping isolation.