In the age of WebMD and other online health resources, many people turn to the internet for self-diagnosis. And now, researchers have found a way to potentially leverage consumers’ search data.

According to a study that will be presented at the American College of Cardiology’s annual scientific session March 10, search engine queries related to common symptoms of heart disease correlated well with geographic and seasonal trends for heart-related hospitalizations. This raises the possibility of using internet searches to track disease trends over time and in different regions, said lead author Conor Senecal, MD, a resident physician at Mayo Clinic.

“It’s very expensive and burdensome to do well-done epidemiological studies,” Senecal said in a press release. “Search data is an imperfect tool, but it may be able to provide some hints or clues into issues that could be further researched with more rigorous methods. It basically provides a cheap and easy way to take a first look at interesting questions.”

Senecal and colleagues analyzed how frequently people in the U.S., United Kingdom and Australia used Google to search for chest pain, chest pressure, chest discomfort or angina from 2012 to 2017. In the U.S., they were able to compare these search trends to state-by-state rates of coronary heart disease hospitalizations through Medicare beneficiary data.

They found hospitalizations and search queries related to symptoms of heart disease showed a 0.8 correlation on a scale of -1 to 1 (0.7 is considered a strong correlation).

For all three countries, the search terms spiked during the seasons in which previous studies have demonstrated the highest risk of cardiovascular disease: winter for the U.S. and U.K. and autumn for Australia. The opposite of those seasons—summer for the U.S. and U.K.; spring for Australia—had the lowest number of heart-related search queries.

“On an individual level, this study shows that people are not just searching for routine symptoms but symptoms that can be life-threatening,” Senecal said. “It suggests that what’s presented to them online can have real-world impacts on their health.”

With this in mind, Senecal said it is crucial that accurate information is readily available on the internet.

“Patients should seek out reputable resources and, if they have any concerns, contact a physician.”