Normal pH Value
May 22, 2022
Source: Cainiu Health
Dr. Li Man
Introduction
The normal pH range of the human body is 7.35–7.45. The body’s fluid environment must maintain an appropriate acid-base balance to sustain normal metabolism and physiological functions. In healthy individuals, plasma pH fluctuates within a narrow, slightly alkaline range; arterial blood pH ranges from 7.35 to 7.45, with an average of 7.40.
pH refers to the acid-base balance of the body. Clinically, blood pH and urine pH are commonly measured to assess the body’s acid-base status.
Normal pH Values
The normal physiological pH range in humans is 7.35–7.45. The body’s fluid environment must maintain an appropriate acid-base balance to sustain normal metabolism and physiological functions. In healthy individuals, plasma pH remains within a narrow, slightly alkaline range: arterial blood pH typically fluctuates between 7.35 and 7.45, with an average value of 7.40. The body continuously generates acidic or alkaline metabolic byproducts and regularly ingests both acidic and alkaline foods. Despite these fluctuations, systemic pH remains relatively stable, regulated by multiple internal buffer systems as well as compensatory mechanisms involving the lungs and kidneys.
Respiratory disorders—such as dyspnea or impaired carbon dioxide elimination—may lead to hypercapnia, resulting in decreased pH and respiratory acidosis. Conversely, frequent vomiting causes substantial loss of gastric acid, potentially leading to metabolic alkalosis, with pH exceeding 7.45.
The process by which the body regulates the quantity and ratio of acidic and alkaline substances to maintain pH within a narrow physiological range is termed acid-base homeostasis—a critical determinant for sustaining normal vital functions. We hope this explanation has been helpful!
