Honestly, I'm not a doctor, nurse or medical professional. I've got my CPR, CRT, and emergency training (thank you options in Cadets

I've kept it up over the years and I'm soooo grateful for it)
So my medical supplies I have are those I know how to use and will be able to make use of! (Yes that's my motto... don't know how to do it... save the space for something I can use.) So I've invested in just about every size bandage you can get your hands on, often through liquidation sales so what would cost $5 is now 0.50!
I have three "kits" One is basic home first aid... which has dinosaur bandages for the kids, polysporin and little stuff like that. This stays in my kitchen and gets the most use.
The second kit is in my truck... it's a bit more involved. I have bandages, scissors, safety pins, polysporin, antiseptic washes, sprays, wipes ... I have pain meds, benadryl, asthma meds, Knife, space blankets, tweezers, and 12 hour pocket heaters. I also have a sealed bag of dehydrated fruit, another of nuts, another of granola, a stash of power bars, and other emergency rations. Water, ... and it starts to go more GHB from there... But basically speaking I could treat a number of injuries while on the go. Most people don't think they'll ever use this but just last week I witnessed a head on collision where some of it came in very handy to quick patch a head wound until the ambulance arrived.
The third kit is in my "prep" area. In it I have a number of books and treatment articles from everything to childbirth (yeah I've done it 4 times but it's good info to have for others) to basic first aid and everything in between. I have the usual bandages in all shapes and sizes, antibacterial everything, pain meds, other meds, etc. A full stocked herbal pantry of natural antibiotics and medications and the how to on using them. Splints, braces, etc. This is enough stuff to set up an on the fly medic station wherever we travel or at home given whatever situation we found ourselves in.
Honestly I'm always looking to expand my knowledge, and marry my little sister off to someone who's actually medically trained... then I can just put him/her into my prep area as... "Doctor" mwhahahaha... are we allowed to prep with people? I keep trying but no dice
