Anions are electrons that have a negative charge. They differ from cations which have a positive charge. In medical terms, the anion gap is the difference between the amount of anions and cations in a person's blood. The anion gap may be high, normal or low. This difference may be caused by diabetes or by a condition known as acidosis. The anion gap test may be part of a routine test which is conducted regularly in order to measure the various vital statistics which may be used to prevent any condition that may be setting in. Such medical tests may also reveal conditions that are at an initial stage and that are not yet producing any symptoms. An anion gap test is also conducted as a routine after a condition has been diagnosed in order to monitor the progress of the treatment or the progression of the condition if it is untreated.
There are many conditions that may warrant an anion gap blood test. These include ketoacidosis caused by diabetes, ketoacidosis caused by alcohol consumption, lactic acidosis and some other conditions. The frequency of conducting such a test depends entirely on the health of an individual. If a person has no symptoms associated with such a condition, then the test is conducted during routine testing which may be done once every year as a person grows older. If there are symptoms or have been symptoms in the recent past, then the tests may be in more rapid succession as the progress and magnitude of the condition are being measured.
The test is conducted using a blood sample. Blood is drawn from the inner side of the elbow joint by a trained medical technician. A blood sample will be collected using a syringe which might cause slight discomfort to the person. There is a small risk of infection due to the test which is avoided by cleaning the area thoroughly before the test and covering the wound with an adhesive bandage after the test. People who suffer from blood clotting problems should inform their doctors about this before such a test so as to avoid excessive bleeding. The sample would be analyzed in a laboratory following which the doctor will be informed of the results. It is also important to inform the technician of any medication that you are consuming at the time. The doctor may also make certain recommendations prior to testing which should be followed.