The pH scale measures how acidic or alkaline a substance is, ranging from 0 (acidic) to 14 (alkaline), with 7 being neutral. The human body must maintain a precise balance between acids and bases for biological processes to function correctly. This regulation ensures that enzymes and proteins operate efficiently and that the body’s cells remain viable.
The Body’s Narrow pH Range
The body’s internal environment, particularly the arterial blood, maintains a remarkably narrow pH window, typically between 7.35 and 7.45. This slightly alkaline range is carefully guarded by sophisticated physiological control systems. Deviations outside this small range can quickly impair cellular function and lead to serious health issues.
The body employs several buffer systems to absorb or release hydrogen ions, thereby stabilizing the pH. The most significant is the carbonic acid-bicarbonate buffer system, which works in conjunction with the respiratory and renal systems. The lungs rapidly regulate acid-forming carbon dioxide in the blood, while the kidneys adjust acid excretion and reabsorption of the alkaline bicarbonate compound.
What Defines Excessive Alkalinity (Alkalosis)
Excessive alkalinity in the blood is a medical condition known as alkalosis, defined as a sustained arterial blood pH greater than 7.45. This indicates that the body’s powerful buffering systems are overwhelmed or compromised. Alkalosis is broadly categorized based on its primary cause: whether it originates from a metabolic process or a respiratory issue.
Metabolic alkalosis results from either an excess of bicarbonate (a base) or an excessive loss of hydrogen ions (acid). Respiratory alkalosis is caused by a deficit of carbon dioxide, which acts as an acid in the blood. This deficit occurs when breathing is too fast or too deep, resulting in the rapid exhalation of carbon dioxide.
Factors Leading to Alkalosis
Clinical causes of metabolic alkalosis often involve an abnormal loss of acid or an accumulation of bicarbonate. Prolonged vomiting is a common cause, as it leads to the loss of highly acidic stomach contents. Certain diuretic medications can also trigger alkalosis by causing the kidneys to excrete potassium and chloride, indirectly increasing bicarbonate.
Other medical conditions, such as severe dehydration or specific kidney disorders, can contribute to this imbalance. Respiratory alkalosis is primarily caused by hyperventilation, which rapidly lowers the carbon dioxide concentration in the blood. This can be triggered by anxiety, panic attacks, pain, fever, or lack of oxygen at high altitudes.
Alkaline Diet and Water
For healthy individuals, consuming alkaline water or following an alkaline diet is highly unlikely to cause clinical alkalosis. The stomach’s naturally acidic environment quickly neutralizes the alkalinity of ingested water and food before it can significantly affect the bloodstream. The kidneys and lungs are so efficient at maintaining the 7.35 to 7.45 blood pH range that only a severe underlying disease or major physiological stress can truly disrupt this balance. Any mild effect from diet is typically limited to transient changes in urine pH, which is a normal function of the kidneys regulating the body’s acid load.
Recognizing the Symptoms and Dangers
Alkalosis can interfere with the central nervous system and muscle function, leading to a range of symptoms. Early signs often include sensory disturbances, such as numbness or a tingling sensation, particularly around the mouth, hands, and feet. Individuals may also experience muscle cramping, twitching, or tremors.
If the condition is moderate to severe, consequences include confusion and disorientation. A highly alkaline environment in the blood can disrupt the balance of electrolytes, such as potassium, leading to hypokalemia. Untreated or severe alkalosis can lead to life-threatening complications, including irregular heart rhythms, seizures, and coma.