The pH of the blood is the negative logarithm (- log) of the hydrogen ion (H+) concentration at any given time. Acidemia and alkalified refer to the actual pH of the blood (table 1-1).

• 血液的pH值是指任一时间H+浓度的负对数（-log）。酸血症和碱血症涉及到血液的实际pH值（表1-1）。