[Saliva diagnostics: a summary of the expanded possibilities].

In hospitals, blood is still the gold standard in diagnostics, but outside hospitals saliva is used more and more. Collecting saliva is not invasive and is therefore easier, safer and cheaper than drawing blood. Saliva secretion itself is also a diagnostic parameter. A low saliva secretion rate may indicate an underlying disease such as Sjögren syndrome and is a risk factor for the occurrence of caries, dental erosion, Candida infections and is associated with upper respiratory tract infections in athletes. Unlike blood, saliva can be collected independently of qualified staff. Saliva can then be sent to laboratories where it can be screened for inherited diseases or virus infections like Covid-19. Tests for which saliva does not need to be sent away but can be processed on site, like pregnancy tests or HIV tests, which are already commercially available, are even easier. The rapid development of biosensors in combination with mobile phone based health apps will lead to new possibilities for saliva diagnostics.