Advantages over Dr. Google: Symptom Checker: How good are diagnoses from the app?

Skin rash, tingling fingers, back pain: Do you research what illness might be behind it? Symptom checkers are intended to be of help - but some apps stir up unnecessary panic, says Warentest.

Is the numbness in my hands harmless - or is it an indication of an early illness? This is a question that only a doctor can answer with any certainty. However, so-called symptom checkers can provide an initial assessment of whether and how quickly you should go to the doctor's office.

This is how it works: Users can enter their complaints on the respective website or in the app. An algorithm then calculates which health problems could be behind them. On top of that, there are often recommendations on how to behave.

But how good are the suspected diagnoses that the digital assistants spit out? Stiftung Warentest wanted to know this and has put ten offers through their paces ("Stiftung Warentest" issue 3/2025).

Some symptom checkers go too far

To do this, the testers developed five fictitious model cases: the symptom checkers were supposed to detect a slipped disc, angina pectoris and depression, among other things. The product testers brought in appropriate specialists and a psychotherapist to provide technical expertise.

There are big differences in the accuracy of the suspected diagnoses. The symptom checkers "Ada" and "Symptomate" deliver reliable results - and both are the overall test winners with a score of 1.9 ("good").

Other offers are much less convincing. Points are deducted for offers that provide a long list of suspected diagnoses without prioritization. "So much choice is of little help to the average person seeking advice," write the product testers. At best, it can be of use to patients who have not found help elsewhere.

One symptom checker even fails with a grade of "unsatisfactory". When describing depressive symptoms - including suicidal thoughts - the answer is: "I don't quite understand that." In the test, the same symptom checker stirs up unnecessary panic when symptoms of a bladder infection are present and advises a visit to the doctor within four hours. But that is not necessary.

Special case of patient navigation

Get to the doctor quickly: If the symptom checker gives this recommendation, the hurdle is often getting an appointment in a timely manner. A symptom checker in the test offers a solution to this problem: the "Patient Navigator" of the National Association of Statutory Health Insurance Physicians

In the test, this offer only came in the middle because Stiftung Warentest found it too cautious with suspected diagnoses. However, it can help patients with health insurance to get a doctor's appointment more quickly - namely if the symptom checker recommends treatment within 24 hours. The "patient navigation" then directs users to a preferred appointment booking with a general practitioner or specialist. There you can get an emergency appointment - online, but sometimes only by phone.

The product testers did not systematically test how well this service actually works, but they did at least do a random check. "During the test, we were able to get appointments at short notice in cities and sometimes in rural areas, often on the same day," they say. They think it's worth trying patientennavi.116117.de.

Advantages over Dr. Search Engine

The question remains: Does it make sense at all to search for your own symptoms using an app? Yes, is the conclusion of the product test. Even if it doesn't replace a visit to the doctor: "A good service is better for initial orientation than a Google search - and can guide patients to the doctor in good time."

Incidentally, symptom checkers can be particularly useful for mental illnesses, says family doctor Jens Lassen in the magazine. Without the app's recommendation, those affected might be more reluctant to go to the doctor.