STEM meets writing
I am a student that thrives in STEM classes. When identifying a struggle I face at school, I would have to say I struggle to find the motivation and focus to write essays. I am a decent writer, but I simply don't enjoy writing. If I were to become a geneticist, or something similar, would I be required to write reports/essays? In addition, what are some medical/stem careers that require a lot of writing?
Let me disappoint you a bit: I think many technical jobs require some writing at some point. I am a software engineer and I have to write use cases, architecture document, user documentation and so on. And as you, writing has never been my strongest suit. But contrary to school, you're not alone. You usually work with other people to discuss your ideas, review your writings and suggest improvements. While I found writing essays and reports at school challenging, it got way better at work. And I wrote a lot.
So I would not be worried too much about writing really. Unless, you are looking at high degree like Ph.D. / researchers that are paid for the reports they generated out of their researches, I do not think this is that terrible.
I will start by answering your specific question on "how much". Most medical/STEM careers will require writing but you would find that the writing style is different depending on what career lane you are in for these fields. If you decide to do work that is research-related, that tends to require a lot of writing mainly because you would typically share the elements of your research work and the results with a body of other researchers. In that space, the details are important so there would be a need to be clear about what you have done and why it was a good thing.
There are other career lanes with the medical/STEM fields where you might be sharing information with decision makers. They tend to focus more on recommendations that can be created to improve a product, tool or service. In these spaces the writing may not be as long, but the conclusions may have to be relayed in a way that is simple and easy to communicate....which brings me to the broader point about writing in general. The awesomeness that a medical/STEM career, specifically a STEM career, can bring is the ability to make improvements, to innovate. If the person who has done these awesome improvements or has designed a better way to do something...if this person isn't able to communicate the goodness of this work, particularly in written form, then many times that awesome work goes unnoticed because no one knows that it's there and/or they haven't been given the information to understand why it matters.
I encourage you to find ways where you can practice your writing style for various audiences and on various topics (even some topics that you may not be very interested in :)) Over time, you may find that your writing doesn't need to be "a lot"...just effective.
Best of luck to you!
I agree with Mickael - pretty much any technical role requires effective writing skills; some more than others, but it's an important life skill that will benefit your whole self. You shouldn't let the fact that writing is challenging hold you back. You could take writing classes in conjunction with services such as Grammarly (grammarly.com/grammar-check) to help you build confidence. Challenges ultimately make us stronger, so I wouldn't let writing deter you from any profession. Mickael's point about PH.D/researchers is also true so unless you're pursuing that route, I doubt you would need to predominantly write all the time for STEM career, let alone habitually write essays.
Best of luck, and feel free to message me if you'd like to discuss further!
To answer the part of the question on what parts of science require more writing; it really depends on exactly what you're doing, but generally the physical sciences tend to be able to convey a lot of information numerically, and while things still need to be described in reports, tables and graphs can often do part of the work in "painting a thousand words". Unfortunately some of the biological and medical sciences do tend to be more qualitative and require a little more description and interpretation than other sciences, but I'd imagine genetics would be one of the more analytical biological sciences and still be very quantitatively driven rather than qualitative. It's the "woolier" qualitative biological sciences like animal behavior and such that would likely require the most writing.