facial expression, surprise
A study reported in BMJ's Emergency Medicine Journal found that certain normal facial expressions were absent in patients with serious heart and lung conditions.Lorenzo Sernicola/Flickr

Inability to exhibit facial expressions may be an indirect indication of certain hidden health conditions, researchers revealed.

A study reported in BMJ's Emergency Medicine Journal found that certain normal facial expressions were absent in patients with serious heart and lung conditions. These patients particularly couldn't display surprise while responding to emotional cues.

For the study, Dr Jeffrey A Kline and colleagues from the Indiana University School of Medicine in US looked at 50 dyspnoea patients with chest pain admitted to the emergency care department of a hospital. Dyspnoea is a health condition that leads to shortness of breath.

Using a laptop webcam, researchers recorded the patient's facial expressions to three visual cues meant to produce emotional responses - a funny cartoon, pictures of a surprised and crying face.

Researchers used a research tool called the Facial Action Coding System (FACS), to measure the patients' facial expressions. Prevalence of different health conditions including acute coronary syndrome, blood clot in the lung, cancer, pneumonia, problems in the main artery aorta or gut were also tested and noted down.

The patients were kept under observation for two weeks. While their stay at the hospital, eight patients experienced serious heart or lung disease and another five without any major health issues developed deadly conditions like heart failure, atrial fibrillation (irregular rhythm of the heart) and chronic obstructive pulmonary disease (lung disease that leads to breathing difficulties).

While comparing the health reports of the participants with facial expressions recorded in the computer, researchers found a direct link between reduced facial expressions and the occurrence of these life-threatening health conditions.

"We believe that due to the gravity of their illness, (these) patients may not have been able to process and respond to an emotional stimulus in the way that would be expected of most people under normal conditions," lead author of the study, Dr Kline and colleagues wrote, according to Science Codex.

The authors also expected that their findings will help avoid unnecessary scannings and improve diagnostic methods related to these conditions.

"The ultimate goal of this work is to provide clinicians with a new physical finding that can be associated with a healthy state to avoid unnecessary (computed tomography) scanning," they added.