Uncertain language can be used to express genuine uncertainty but can also be used to manage face (e.g., by softening bad news). These conflicting motivations can create ambiguity in health communication. In this preregistered two-part experiment, participants assumed the position of a health specialist and wrote a letter communicating either a certain or an uncertain medical diagnosis. This was addressed to either a patient (high face threat) or the patient's family doctor (low face threat). Letters written under high face threat contained more words and more dispreferred markers (e.g., sorry, unfortunately) than those written under low face threat. The number of explicit hedges (e.g., possibly, maybe) did not differ as a function of face threat. Time taken to write the letters was elevated only in the condition where face threat was high and the diagnosis was uncertain, suggesting that the joint pressures of communicating uncertain information in a tactful way increased the task demands. Our data demonstrate that participants spontaneously produced dispreferred markers (but not explicit hedges) to manage face and that face management is more taxing under uncertainty. Ratings from a second set of participants indicate that face management strategies did not affect the perceived meaning or manner of the message. For open materials, data, and code, see https://bibliotheek.ehb.be:2102/10.17605/OSF.IO/ZU2AN.