A first step would be to tell us something about the hardware:
What CPU, GPU, RAM, harddisks are in the machine?

Next would be to tell us something about the project you are running: are you running multicorders, replays, movie files?

Also what software is running in the background: any chrome tabs open at the same time as streaming?

Streaming settings can also help: if you encode on the 'veryslow' preset, you need a beefy machine for example.

Finaly a screenshot of statistics (found in the bottom right corner) could help sort out where the frames are dropped: on input, dropped by the gpu, or perhaps frametimes of the incoming signal are not regular.