This has happened to me over the past few months. I am in my late-20s, and I never struggled with stuttering or similar speech issues in adulthood before, though I did need to work with a speech pathologist as a small child. It comes up about once or twice a week, generally when speaking to a supervisor or client at work. It came up daily this past week while I was visiting my parents and we navigated some stressful incidents together. I told my boyfriend about it this morning and asked if I should see a doctor, in case it's related to a car accident I was in a few months ago or a brain tumor. He is a pediatrician -- so a doctor, but speech issues in adults it far from his specialty. He told me that it's unlikely that it's related to the car accident or a brain tumor and much more likely to be related to the stress I've been under at work recently. Any evaluation would probably require an MRI, which could take a long time to schedule. However, he said that I should see a doctor if I do feel stressed about and I need the peace of mind. I hope hearing about my experience is useful for you!