If that headache plaguing you this morning led you first to a Web search and then to the conclusion that you must have a brain tumor, you may instead be suffering from cyberchondria.

On Monday, Microsoft researchers published the results of a study of health-related Web searches on popular search engines as well as a survey of the company’s employees.

The study suggests that self-diagnosis by search engine frequently leads Web searchers to conclude the worst about what ails them.

The researchers said they had undertaken the study as part of an effort to add features to Microsoft’s search service that could make it more of an adviser and less of a blind information retrieval tool.