Li H, et al. - Through a retrospectively gathered data for individuals who were treated for hyperhemoglobinemia and had available brain CT scans, researchers examined the association between hyperhemoglobinemia and pseudo-subarachnoid hemorrhage (SAH) and investigated the underlying mechanism. In the hyperhemoglobinemia group vs control group, a significantly greater incidence of pseudo-SAH was observed, and within the hyperhemoglobinemia group, among those with a hemoglobin value of ≥ 210 g/L vs those with a hemoglobin value of < 210 g/L, it was significantly higher. Spearman correlation analysis and logistic regression analysis revealed an important association between pseudo-SAH and hyperhemoglobinemia however there was no notable association between pseudo-SAH and gender, COPD, or smoking history. Therefore, in pseudo-SAH, hyperhemoglobinemia could be a contributory factor. Clinicians should be conscious of this phenomenon and be alert to differentiate pseudo-SAH from SAH, especially in individuals with hyperhemoglobinemia.