ObjectiveTo investigate the intervention effects of modified Linggui Zhugan Tang （LGZGT） on patients with obstructive sleep apnea-hypopnea syndrome （OSAHS） of the spleen deficiency and dampness obstruction with blood stasis type， reveal its possible mechanisms， and provide a theoretical basis for the clinical treatment of OSAHS with traditional Chinese medicine （TCM）. MethodsEighty OSAHS patients with spleen deficiency and dampness obstruction with blood stasis were randomly assigned to a control group and an observation group （1∶1） using a random number table， with 40 patients in each group. The control group received standard basic treatment combined with oral Doxofylline tablets， while the observation group received standard basic treatment combined with modified LGZGT. Serum levels of macrophage migration inhibitory factor （MIF）， microRNA-223 （miR-223）， and interleukin-18 （IL-18） were measured by enzyme-linked immunosorbent assay （ELISA）， and the mRNA expression levels of MIF， miR-223， and IL-18 were measured by real-time quantitative polymerase chain reaction （Real-time PCR）. After two months of treatment， the total clinical efficacy， apnea-hypopnea index （AHI）， lowest nocturnal oxygen saturation （LSpO₂）， body mass index （BMI）， TCM syndrome scores， and expression levels of MIF， miR-223， and IL-18 before and after treatment were compared between the two groups. Correlations between MIF， miR-223， IL-18 and AHI and LSpO₂ were also analyzed. ResultsCompared with the control group， the observation group showed a significantly higher total clinical effective rate （P<0.01， Z=-3.49）. Within the control group， no significant changes were observed in AHI， LSpO₂， BMI， TCM syndrome scores， or MIF， miR-223， IL-18 levels and their mRNAs after treatment. In the observation group， AHI， BMI， TCM syndrome scores， and MIF and IL-18 levels and their mRNAs decreased significantly， while LSpO₂ increased significantly （P<0.01）. After treatment， compared with the control group， the observation group exhibited significantly lower AHI， BMI， TCM syndrome scores， and MIF and IL-18 levels and their mRNAs， and significantly higher LSpO₂ （P<0.01）. Correlation analysis showed that MIF and IL-18 were positively correlated with AHI （P<0.01） and negatively correlated with LSpO₂ （P<0.01）， whereas miR-223 was negatively correlated with AHI （P<0.01） and positively correlated with LSpO₂ （P<0.01）. ConclusionModified LGZGT may improve OSAHS of the spleen deficiency and dampness obstruction with blood stasis type by reducing airway inflammatory factors， alleviating airway inflammation， relieving airway edema and stenosis， and improving airway obstruction.