pH Levels in Humans

The pH levels in the human body are directly related to the normal metabolic function of many different organ systems. The pH levels in the blood and tissues are controlled by an internal buffer system and should remain at a fairly constant level. Disease and organ damage can result if the pH levels in the blood remain too high or too low for an extended period of time.

pH

• The pH is a measure of the acidity or basicity of the blood and tissues in the human body. It is measured on a scale of one to fourteen: seven is considered neutral; any number below seven indicates acidity, and above seven indicates basicity. The normal blood ph level is between 7.35 and 7.45. If the level increases to 7.6 or decreases to 7.2, this indicates a life threatening problem in the body. It is important to know that the pH levels in urine, saliva and sweat can differ greatly and are influenced by the time of day, food we eat and environmental factors and may not necessarily indicate a health concern.

pH Control

• Our body relies on three systems to help maintain the pH level in the blood and tissues. The three systems are: blood and tissue buffers, the lungs and the kidneys.

  Bicarbonate, protein and haemoglobin are buffers. Buffers bind with hydrogen ions, preventing the hydrogen ions from altering the pH level of blood and tissue.

  The respiratory system is the most important system for control of normal pH levels. Carbon dioxide, which is acidic, is a waste product of oxygen. Since oxygen is required by every cell in the body, it is constantly being excreted into the blood. The blood carries the carbon dioxide to the lungs where it is excreted during exhalation.

  The kidneys help regulate the bicarbonates and excess hydrogen ions in the blood. They reabsorb the necessary bicarbonates and excrete the excess hydrogen ions.

Acidosis/Alkalosis

• Acidosis occurs when the blood has an increased amount of acids and the pH levels fall below 7.35. Alkalosis occurs when the blood has an increased amount of bases and the pH rises above 7.45. Acidosis and alkalosis are not diseases but are indicative of a problem in the body. There are two specific classes of acidosis/alkalosis: metabolic and respiratory.

Metabolic Acidosis/Alkadosis

• Metabolic acidosis occurs when the body produces an excessive amount of organic acids, when an acid is ingested or when the kidneys are not functioning correctly. Metabolic acidosis causes nausea, vomiting and fatigue. People with mild metabolic acidosis may also have changes in respiration, breathing faster and deeper. These symptoms will progressively worsen and eventually lead to shock, coma and death.

  Metabolic alkadosis occurs when the body loses too much acid, such as stomach acid lost during vomiting, or has too much bicarbonate in the blood. Kidney problems can also lead to metabolic alkadosis. Metabolic alkadosis causes irritability, muscle cramps and spasms and muscle twitching.

Respiratory Acidosis/Alkalosis

• Respiratory acidosis is caused by a buildup of carbon dioxide in the blood. This is a result of decreased lung function, which can be caused by emphysema or chronic bronchitis, neurological and neuromuscular diseases that affect the muscles of the chest, as well as drug or alcohol overdose. Respiratory acidosis causes headaches and drowsiness, which can quickly lead to stupor and coma.

  Respiratory alkalosis occurs when the body hyperventilates (breaths too quickly), and expels too much carbon dioxide from the blood. This can occur in cases of extreme anxiety, pain, fever and aspirin overdose. Respiratory alkalosis can cause dizziness; however, it usually corrects itself with the return of normal breathing.