Objective: This study aimed to report the effect of Baekhogainsam-tang on brain fog.

Methods: A 59-year-old female patient complained of brain fog and waking up frequently during the night. Based on the Shanghanlun disease pattern identification diagnostic system, the patient was treated with Baekhogainsam-tang. The result was evaluated using the score.

Results: After administration of Baekhogainsam-tang for 45 days, the MFI score decreased from 89 to 40. The average number of instances of waking up during the night decreased from 3 to 1.5.

Conclusions: Some cases of brain fog can be treated by Baekhogainsam-tang.

Key words: Baekhogainsam-tang, Brain fog, disease pattern identification diagnostic system based on Shanghanlun provisions (DPIDS)

Please define abbreviations at first mention in the text.