Overnight oximetry tests serve a very crucial role in treating certain diseases and health conditions when the person has respiratory issues, problem in breathing through lungs directly, the level of arterial blood gas is low, or under circumstances where observation of oxygen saturation in the hemoglobin is needed.

What is Overnight Oximetry Testing?

Overnight oximetry or Pulse Oximetry is a simple test done in order to observe the level of oxygen saturation in arterial blood. It can easily be done at home through an Independent Diagnostic Testing Facility (IDTF) oximetry company.

A sensory clip is attached to your finger. On the other end, this clip is connected to an oximeter, the device that administers the tests and observes the level of oxygen in blood.

The device functions on the mechanism of a red ultraviolet ray that is passed through the area of body on which the clip is attached. One side of the clip sends the ultraviolet ray which is received on the other end. The device measures the heart beat rate and the contents of the blood from which it determines the level of oxygen present. The color of the blood indicates this; a deeper red would be suggestive of higher oxygen concentrated blood, while a bluish shaded blood is indicative of low oxygen levels.

How Does It Work?

The data collected through the clip is stored in the oximeter throughout the course of the night. The results are given in the form of a graph which is to be interpreted by the medical professional or doctor overseeing the overnight oximetry test at the IDTF. Seeing the peaks and pits on the graph, he will determine if the graph indicates any abnormal drops in the oxygen levels. These drops are called desaturations and the fall of oxygen levels below 90 is considered to be low oxygen saturation.

It is quite a common experience in severe lung or respiratory diseases. These include

• Severe cases of asthma 
• lung cancer or any other type of lung disease, 
• cystic fibrosis 
• bronchopulmonary dysplasia 
• trauma or damage to the respiratory system, etc

Other conditions like sleep apnea, heart failure, Pneumonia, etc also require overnight oximetry testing at times.

Risks and Benefits of Home Oximetry or Overnight Oximetry

In serious conditions, home based oximetry testing or overnight oximetry can help to determine if you require oxygen therapy at home. Especially in case of sleep obstructive apnea, home oximetry can prove to be the first step for screening. And all this could be done at the comfort of one’s own home.

However, while this testing method has many benefits, there are some risks and potential problems associated with it as well. There is no serious harm posed by this testing method but minor errors can create problems. For instance if the device is turned off at night but you forget to turn it back on later, the reading would not be collected for the entire night. Also, the test has very limited prospects as it does not provide complete information needed for the diagnosis of various problematic conditions like sleep apnea, etc.