Acidosis and Alkalosis
First, in the human body, an acid is the presence of a free hydrogen ion (H+) in the fluids found in the body. This is an important point.
If the hydrogen ion is chemically combined with some other chemical it is not affecting the pH of the body, at that time.
The normal pH of the human body is 7.42. This is an average pH. The range for pH extends from a pH of zero to a pH of 14. Any pH value near 1 is extremely Acidic (lots of free hydrogen ions). Any pH value near 14 is very Basic (very few free hydrogen ions).
The normal pH value of the human body is slightly Basic. When you look at pH what is the significance of the number 7.42? How do we interpret them?
The definition of pH is meaningless when it come to what is happening to the patient. If the pH falls from a value of 7.42 to 7.41 the increase in the number of free hydrogen ions is 10% (percent).
If it drops to 7.32 the increase in the number of free hydrogen ions is 100% (percent).
Yes, it has doubled. A patient who has a drop of one tenth of a pH value is in a serious Acidosis. Think trends are important? Using an old Minnesota phrase, "You Betcha!"
Going the other way, if the pH rises to 7.52 the number of free hydrogen ions has declined 100% (percent). The patient is in a serious Alkalosis.
Did we really need a formal definition of pH to understand what its values tell us.?
Remember, with electrolytes, time of decision is critical.