看一下白細胞分類，是不是都減少，還是哪一單項減少的更為明顯。如果感覺一切正常，不經常感冒或有其它感染，也許問題不大。回中國略增高，很可能是對一些輕微感染的反應，比如空氣汙染。另外，如果當你發生感染，白細胞能迅速升高，說明你的造血功能正常。文獻裏是這樣說的：
"For adults, counts of less than 1,500 neutrophils （中性粒細胞）per microliter of blood are considered to be neutropenia. Some people have lower-than-average neutrophil counts, but not an increased risk of infection. In these situations their neutropenia isn't a concern. Neutrophil counts less than 1,000 neutrophils per microliter — and especially counts of less than 500 neutrophils per microliter — are always considered to be neutropenia, where even the normal bacteria from your mouth and digestive tract can cause serious infections".
