A Valsalva manoeuvre is an effort to exhale without letting air escape through the nose or mouth. People often use a Valsalva manoeuvre during some common activities, such as straining to have a bowel movement or blowing a stuffy nose.

A Valsalva manoeuvre is not normally harmful. But it may cause irregular heart rhythms in some people who have certain types of heart disease.

A person may be asked to do a Valsalva manoeuvre during certain medical tests or exams. During the test, a person is asked to try to breathe out using the stomach muscles and diaphragm but not let any air out through the nose or mouth.