Cutting-edge technology is being used to detect diseases through olfactory senses.
Written by Susan Parker | Updated on June 22, 2025
Reviewed by Susan Parker
11 sources cited
Overview
It is widely recognized that various diseases emit a unique scent or "breathprint" that can serve as an early indicator of the condition. Traditionally, animals like dogs and cats have been known to detect these odors and identify illness due to their acute sense of smell. However, modern medicine is now turning to a more advanced detector known as an electronic nose, or eNose.
From asthma and Alzheimer's disease to COVID-19 and cancer, eNoses present a potent, rapid, and non-invasive method for diagnosing illnesses. They also have valuable applications in disease screening, prognosis, and treatment. Let's delve deeper into this innovative technology.
Exhaled breath carries thousands of tiny aerosol particles and volatile organic compounds (VOCs). These compounds, as demonstrated in cases like COVID-19 and other respiratory conditions, can facilitate disease transmission. What might not be common knowledge is that VOCs present in breath are also linked to biochemical and metabolic processes and undergo changes during abnormal cellular activity, resulting in a distinct disease signature.
Although the alteration of VOCs has been acknowledged since the 1970s, the technology to leverage this insight was previously unavailable. However, with advancements in computational analysis and the integration of machine learning, this landscape has transformed, as evidenced by the surge in research over the past two decades.
“Will Guide Future Treatment in Oncology”
Besides breath, blood and urine also emit unique scents. At a medical conference in June 2021, the University of Pennsylvania unveiled a test designed to detect vapors emanating from blood samples.
This test successfully distinguished between individuals with ovarian or pancreatic cancer and those with benign tumors or healthy individuals without tumors. The accuracy rates were remarkable, achieving 95 percent for ovarian cancer and 90 percent for pancreatic cancer.
Dr. Charlie Johnson, the presenter of these findings, expressed optimism, stating, "The results are highly promising. The data indicates our ability to identify these tumors at both advanced and early stages, which is truly exciting."
Lung cancer has been extensively studied, with 37 research papers dedicated to it. Through these studies, researchers managed to differentiate between individuals with and without lung cancer with an accuracy exceeding 80 percent.
In a study conducted in 2018 involving 252 lung cancer patients and 223 individuals without cancer, the eNose accurately distinguished between the two groups with over 90 percent accuracy.
Subsequently, the following year, the eNose successfully identified lung cancer patients responsive to immunotherapy with an impressive 85 percent accuracy rate. This surpasses the current gold standard measurement based on blood tests and cell cultures!
Professor Michel van den Heuvel from Radboud University in the Netherlands, the lead researcher, firmly believes that eNoses will "emerge as a vital diagnostic tool and will steer the course of future treatments in oncology and various other medical conditions."
One such condition under the microscope is Alzheimer’s disease.
Accurately Identifies Alzheimer’s Disease
In a preliminary study, researchers assessed breath samples from 100 individuals and successfully differentiated between healthy adults and those with Alzheimer’s disease with an accuracy rate of 83 percent. They noted that this technique "holds significant promise" as a diagnostic tool for a disease that lacks widely available definitive diagnostic tests aside from post-mortem examination.
Asthma represents another area where eNoses could revolutionize diagnosis since VOCs in exhaled breath mirror specific molecular processes linked to the chronic inflammation characteristic of the condition.
Besides diagnosis, VOCs can aid in assessing the efficacy of therapies for asthma patients. Upon reviewing existing studies, researchers highlighted that VOCs are among the most promising biomarkers for diagnosing and monitoring asthma.
Dr. Charlie Johnson is also engaged in a project aimed at developing a rapid, portable, user-friendly breath test for COVID-19. Odor testing has already demonstrated a high level of accuracy in distinguishing the body odor emitted by T-shirts worn by COVID-positive individuals from those worn by COVID-negative individuals. Dr. Johnson described this initiative as a swift and precise endeavor.
VOC Testing Holds Promise For Diagnosing Almost any Illness
VOC biomarkers have been identified in numerous other diseases. Given that most health status changes can be linked to metabolic shifts, it should be feasible to detect biomarkers for nearly any disease.
Professor Andrew Bush, a consultant pediatric chest physician from the United Kingdom involved in eNose trials, shares his enthusiasm for this innovative technology.
“As a clinician, I see vast potential in breath testing. While it is still a work in progress, the latest research is astounding, and it wouldn't surprise me if, in the near future rather than in the distant future, I would be treating patients with a device they could simply blow into for a diagnosis or to determine the most effective treatment.”
