Can arterial blood gases indicate interstitial pneumonia? Do I need to have other blood tests? Arterial blood gas analysis is not indicative of interstitial pneumonia! Although most interstitial pneumonia is severe enough to develop type I respiratory failure, there are many other diseases in which type I respiratory failure can occur. This is because arterial blood gas analysis can provide information on the overall pH of the blood, the levels of oxygen and carbon dioxide in the blood (based on these indicators to determine the presence of hypoxemia, type I respiratory failure characterized by hypoxia, and type II respiratory failure characterized by carbon dioxide storage), electrolytes in the blood (whether there is a disturbance in electrolytes), anions such as bicarbonate (for determining the presence of metabolic acid-base imbalance), etc. In the diagnosis of interstitial pneumonia, a variety of other hematological tests are required, such as immunological indicators (including the detection of various autoantibodies, anti-neutrophil cytoplasmic antibodies, blood immunoglobulins, rheumatoid-related antibodies), sometimes oncological indicators, indicators of infection, etc., depending on clinical needs, since all diagnoses of interstitial pneumonia require the exclusion of other diseases.