Check out this service where lots of people from all of the country look for gently used furniture and numerous other household items. They not only have this free service, but they also have a job section. In that job section, hundreds of clients log in and add almost hundreds of job listings. Some are just regular typing/writing jobs. But quite a few are health-related writing careers.
Scan over the listings of health writing topics and as you find the listings that sound promising to you, considering sending your information and job qualifications. Another thing you can do to speed up the search is type in health writing in the search section of the website. You'll cut right through to the listings specifically looking for someone who writes about health topics.
Once you find these listings, pay attention to the information they're asking you to send. Some of them might be from a website that publishes regular health articles for a certain amount of pay. Other Listings are more specific and want proof of what your education is about the topic. They'll want to know if you have history as a nurse or experience working with conditions.
Send in your writing resume and add a link to writing samples you have on a website. If possible, make sure the writing is related to the health topics they need to have written about. Maybe it's skin conditions. Send in writing samples from some work of yours that has already been published and has your byline on it. If it was ghostwritten (not using your real name) you cannot use it. It has to have your byline.
Another great way to get writing work in the health industry is checking out a bidding site. You have to register and put up a profile. In your profile, you add information about your experience. That is where you make sure you list your medical knowledge and experience. Start with a basic profile (for free) or get a step up where you pay a small fee but have access to a lot more work.
Once you get a profile going, you look up writing work for a writer who is new on the site to get a bit of a reputation. Once you get a writing gig or two, you'll be on the path to getting steady writing work in the health field.