If you are under graduate students then select a topic which is related to the prevalence & frequency, b/c under graduate research study aims to understand how to do a research. Select any topic according to the FINER formula of research.

Look around you with child like curiosity and ask questions, though many of them sound childish. A child is a real scientist. Do not believe everything on face value because it is in the books. Find out some lacuna in the present day understanding. Use your own imagination. Some basic science books may provide some clues. Rest is your luck. At under-graduate level, even joyfully rediscovering an old hypothesis and trying to critically evaluate it in unbiased way is a good basic research

Read older publications. There may be some unsolved problems that you could investigate.

As an undergraduate you can focus on a study that involved retrospective data.

This will require ethical clearance from the institution in which you are enrolled in and the diagnostic laboratory from which you will extract the results.

This method is effective in learning how to conduct research, analyze and interpret scientific data.