玻尔效应（英语：Bohr effect），1904年由丹麦生理学家克里斯蒂安·玻尔首先提出，即：氢离子（低 pH）和二氧化碳会降低血红蛋白与氧气的亲和力，促进血红蛋白释放氧气。

产生该效应的原因为质子与二氧化碳可与血红蛋白（Hb）分子特定位点结合而促进后者从松弛态（relaxed state，R态）转变为紧张态（tense state，T态）。相关的基团有血红蛋白 α 亚基的 N 端氨基以及 β 亚基的 His-146 和 α 亚基的 His-122 两个咪唑基，这些基团在 Hb 处于紧张态时都是高度质子化的。Hb 与氧气的结合促使质子解离。因此当 pH 降低、质子浓度增高时，将有利于上述基团处于质子化的形态，从而稳定 T 态，抑制 Hb 与氧气的结合。

The Bohr effect is a physiological phenomenon first described in 1904 by the Danish physiologist Christian Bohr, stating that haemoglobin's oxygen binding affinity (see Oxygen–haemoglobin dissociation curve) is inversely related both to acidity and to the concentration of carbon dioxide. That is, an increase in blood CO₂ concentration, which leads to a decrease in blood pH, will result in haemoglobin proteins releasing their load of oxygen. Conversely, a decrease in carbon dioxide provokes an increase in pH, which results in haemoglobin picking up more oxygen. Since carbon dioxide reacts with water to form carbonic acid, an increase in CO₂ results in a decrease in blood pH.