You wouldn't expect someone suffering from serious heart and lung conditions to be wearing a smile.

But who knew that it could work to their medical advantage in a pinch?

According to research published in Emergency Medicine Journal, patients with chest pain and shortness of breath who had a potentially serious heart or lung condition had a significantly reduced range of facial expressions.

Researchers showed 50 adults with shortness of breath and chest pain three different images: a humorous cartoon, a surprised face and someone crying. They compared these findings to the patients' objective medical diagnoses. Voila. The faces of those with heart and lung conditions showed less emotion.

This is helpful information to emergency physicians who are under pressure to make diagnoses quickly, so patients with serious conditions can get the right care quickly. Time is of the essence.

The reason for the flat affect could be as simple as patients with grave illnesses aren't able to process emotional stimuli normally.

Sometimes good, old-fashioned observation and logic - in medical and life decisions - are the first places to look for help.