This results in cyanosis in the lower extremities, a blue or purple discoloration of the skin; that's the result of deoxygenated blood mixing with oxygenated blood.

这会导致下肢的发绀，即皮肤青紫，是由缺和合混合造成的。

The increased CO2 levels in the blood can get so bad that some people develop cyanosis, which is a blue discoloration of the skin, and this is why patients with chronic bronchitis are sometimes referred to as blue bloaters.

中二含量升高可能引起发绀，即患者的皮肤会，这就是为什么慢支患者又被比做鲱鱼。