The balance of acid and bases in the body can be measured by a number called pH. A pH of 7.4 is normal for the blood. A pH below this level is a measure of excess acid, while a pH above is a measure of excess base. Problems of the acid and base balance can be divided into respiratory and metabolic causes.
Respiratory Problems Causing Excess Acid
Carbon dioxide is a product of energy production by cells. The blood carries carbon dioxide to the lungs to be expelled into the air. When it builds up, carbon dioxide combines with water to make carbonic acid. Therefore, excess carbon dioxide leads to excess acid. Problems that decrease the rate or volume of breathing relative to the production of carbon dioxide by the body will cause respiratory acidosis, according to the National Institutes of Health. Examples include use of narcotic drugs, which slows the respiratory rate, and asthma, which can narrow the airways and interfere with exhalation.
Respiratory Problems Causing Excess Base
Similarly, if the rate of breathing or the volume of breath exceeds the acid production by the body, the lungs will expel too much carbon dioxide, lose too much acid, and the blood will have too much base. According to the Merck Manual, this is called respiratory alkalosis. Examples of conditions that cause this include breathing heavily from an anxiety or panic attack or a fever that induces excessive breathing.
Metabolic Problems Causing Excess Acid
Metabolic problems causing excess acid in the blood are from a source other than the lungs. There are many causes of metabolic acidosis and different ways of classifying them. According to the National Institutes of Health, one possible cause is the buildup of lactic acid, which can occur with alcohol use, exercise and relative oxygen deprivation. Other causes include diabetic acidosis and loss of the base bicarbonate from the kidneys into the urine or through the GI tract with diarrhea.
Metabolic Problems Causing Excess Base
Excessive loss of acid or the buildup of base from a source other than respiration is called metabolic alkalosis. According to the Anaesthesia Education Website, the two most common causes of metabolic alkalosis are vomiting and diuretics. The stomach uses hydrochloric acid to digest food. Vomiting expels the acid from the body, causing loss of the acid and buildup of base. Diuretics can cause the buildup of too much base through their actions on the kidneys.
