I get asked about checking the blood PH or urine PH because more and more people are trying Alkaline diet. They are following the diet and want to monitor if the diet made a difference. Just like if a diabetic patient cut down on their intake of sugar, or carb, they would expect a lab test of the blood sugar improves. This is not the case for blood PH. No matter what you eat, your body maintain the normal range of PH in the blood. The blood PH stays between 7.35-7.45.
When I take care of ICU patients who are critically ill, their blood PH can be low and this is a life threatening condition because the body is unable to maintain it's balance.(homeostatsis). I remember drawing the blood gas every few hours as an intern and adjusting their ventilator and the IV fluid to provide more or less alkaline. Our amaxing body can maintain the balance of acid and alkaline mainly by two organs: the kidney and the lung. When the body has too much acid because of infection (sepsis), severe heart disease, or lung disease, causing deprivation of oxygen, (hypoxisi), our lung will try to breath out more carbon monoxide, and our kidney will release more acid in the urine. The body is so critically ill, that we will be able to detect by a test called Blood Gas. It is NOT a routine test that you would need on a physicial. I pray that you will not need this test, because it is quite painful because it is drawn from the artery at your wrist.