I usually do have a platelet count on the low side, so bruising is often an issue for me. I have had this since childhood. There have been times my platelet count has been very low.
From experience, I can tell you that there are various blood tests that can be ordered to rule out potential health conditions. There is also something called a "bleeding time" test, which basically determines if you are at risk for hemorraghing. I wonder if any of your meds could be causing this and it might be something to inquire about.

There are many natural type things you can do that might help. If your doctor okay's it...you could take a Vitamin K tablet temporarily...when your bruises are at their worst.
Also, eat pineapple frequently (if it doesn't interfere with your meds). Then, use Arnica cream on the bruises themselves. These are just little things I have done that have helped to make the bruises heal faster.