Breath test for stress - Telegraph But lead author Professor Paul Thomas said: "If we can measure stress objectively in a non-invasive way, then it may benefit patients and vulnerable people in long-term care who find it difficult to disclose stress responses to their carers, such as those suffering from Alzheimer's." Breath profiling has become an attractive diagnostic method for clinicians, and recently researchers have found biomarkers associated with tuberculosis, multiple cancers, pulmonary disease and asthma. It is still unclear how to best manage external factors, such as diet, environment and exercise, which can affect a person's breath sample. Prof Thomas said: "It is possible that stress markers in the breath could mask or confound other key compounds that are used to diagnose a certain disease or condition, so it is important that these are accounted for." He added that the stressful situation created in the experiment - a tricky arithmitic test - was designed to simulate the condition as far as possible, but within the constraints of ethics. Further and more extensive testing would be required, he said. He explained: "What is clear from this study is that we were not able to discount stress. It seems sensible and prudent to test this work with more people over a range of ages in more normal settings. We will need to think carefully about experimental design in order to explore this potential relationship further as there are ethical issues to consider when deliberately placing volunteers under stress. Any follow up study would need to be led by experts in stress.