A basic functional unit of the body is the cell. Specialized cells make up different organs. Liver cells help detoxify the blood, and heart cells conduct electrical currents and contract together to cause the heart to beat. Proper functioning of the cells requires an appropriate environment of minerals, acids, oxygen, foods and other nutrients. High levels of acid can disrupt the normal function of the cells and the body, and requires diagnosis and treatment with the consultation of a health-care professional.

Measures of Acid

Chemically, acid is defined in several different ways. A frequently useful definition for biology is the Bronsted-Lowry acid-base theory. In this theory, an acid is defined as a molecule that is able to donate or lose a proton, which is also a hydrogen ion. A base is a molecule that is able to accept the proton. The acidity of a solution is typically measured by pH. A pH of 7 is neutral. A pH below 7 is acidic, and a pH above 7 is basic, or alkalotic. Normal blood pH is 7.4. Having acid in the blood means that the pH is below 7.4, and excessive protons may be found in the blood.

Causes of Acid in the Blood

Acid in the blood is known as acidemia, and acid in the tissues is termed acidosis. There are three basic classifications for causes of acidosis. Respiratory acidosis involves increased acid from decreased release of carbon dioxide out of the body through the lungs. Metabolic acidosis is caused by the body producing too much acid or not eliminating enough acid through the kidneys.

Respiratory Acidosis

The breakdown of food for energy in cells produces carbon dioxide. In the blood, carbon dioxide is converted into carbonic acid, transported to the lungs, converted back into carbon dioxide and expelled. Disorders that decrease the rate or volume of breathing cause carbon dioxide, hence carbonic acid, to build up and acidify the blood. Drugs such as opiates can slow down the breathing. Strokes or other problems in the brain can dysregulate the breathing. Problems with the muscles or nerves can impair breathing as well.

Metabolic Acidosis

Kidney problems, such as chronic renal failure, can cause metabolic acidosis. Two of the most common causes of chronic kidney failure include high blood pressure and diabetes. In many kidney diseases, the kidneys are unable to secrete acids such as sulfuric and phosphoric acids. Another cause is overproduction of acid by the body. For example, in suddenly uncontrolled type I diabetes, the body cannot utilize the sugar glucose and produces chemicals called ketones to feed the body. Some of the ketones are acids; this condition is known as ketoacidosis.