<ul><li>A score of 80 percent or more of the predicted value is considered normal. If the results are abnormal, more tests such as blood tests or chest X-ray is ordered.</li><li>Test results enable the healthcare provider to diagnose and decide the treatment of certain lung disorders or may be used to check lung function before surgery or other procedures in patients who have lung or heart problems, who are smokers, or who have other health conditions.</li></ul><p>Avoid in case of - </p><ul><li>A heart attack or stroke in the past three months</li><li>A large aneurysm of a major vessel</li><li>Active tuberculosis (TB) or respiratory infection, such as a cold or the flu</li><li>A major head injury</li><li>Recent eye surgery</li><li>Recent belly or chest surgery</li><li>Confusion</li></ul><p>Alternatives include Impulse oscillometry (IOS)</p>