For individuals with health-related anxiety, the internet can be very dangerous. As online diagnosis sites become increasingly popular, doctors are warning about the mental health effects of self-diagnosis and urging those concerned about their health to seek professional help before jumping to drastic conclusions about their aches and pains, the Washington Post reports.

The latest edition of the Diagnostic and Statistical Manual of Mental Disorders defines people who worry excessively about their health as having either somatic symptom disorder or illness anxiety disorder rather than hypochondriasis, a term that the manual dropped in 2013. However, many doctors think the new terms are far too general and may lead to unnecessary mental illness diagnoses. And because the classifications are new, there is no data on how many people may be suffering from clinically significant levels of health anxiety.

To describe the unique connection between health-related internet searches and anxiety, some researchers have coined the term “cyberchondria.” Recent studies show that between 60 and 80 percent of people today search WebMD and the Mayo Clinic for health information. According to a 2013 survey, 35 percent of respondents said they had searched the web looking specifically to diagnose a medical condition.

This is worrisome to many doctors, who say that as professionals, they are far more likely to deliver accurate answers about people’s ailments than a web search. In a 2016 study, online symptom checkers diagnosed themselves correctly only 34 percent of the time. Doctors, on the other hand, had an accuracy rate of 72 percent.

Recent studies also show that people who search for symptoms on the internet may be more likely to jump to catastrophic conclusions. They may look for information that confirms their worst suspicions. And they also tend to resist reassurances from medical professionals when nothing turns out to be the matter. Once this health-related stress becomes so preoccupying that it interferes with an individual’s life, experts say it’s important to get help from a psychologist or psychiatrist.

But that’s not to say that online health research is entirely worthless. Sometimes, a little anxiety can motivate people to finally seek the health care they need. But doctors warn that it’s important to check in with a professional about any serious health worries.