People carry different things depending on their experience. Besides band-aides and blister treatment, there are other stuff to add in your medical kit.
For example, burn cream, Tums, Triple antibiotic, gauze pads, surgical scissors, clamp, hooked needle, surgical thread, medical tape, athletic tape, Ibuprofen, Benadryl, Tylenol, Migraine meds, Hydrocodone, Morphine, Anti-nausea, Antibiotics, Elevation sickness meds, eye patch, erythromycin ointment, tweezers, two splints, and...misc. stuff.
Most backpackers or hikers would like to learn from others. There is something I hadn't thought of before. And here is a question, do people care how heavy/light their medical kit is?
My first aid kit is the one thing that has gotten bigger as my skills have grown better. Each kit should only be filled with stuff you are able/skilled to use, that is to say, bring something you don't know how to use is no more than pack stone in your backpack.
Tweezers. I tend to find the cacti ... Although on our recent Big Bend trip, we needed them for the daughter who sat on a cactus. (the apple doesn't fall far from the tree!) Also - a thermometer is recommended if you camp with kids or babies.
Adventure Medical Kit UL .7 works also, but you've got to get familiar with all its components. I supplement it with a tensor bandage and a few of drugs (for pain of varying degrees, allergies, nausea, etc). One thing I've started carrying is charcoal tablets, they are with many usages.
Also, in keeping with my knowledge and skills. We use a lot of bandaides for minor ouches, and ibuprofen is a dietary staple :p I also carry migraine pills for myself. Moleskin, antidiarrhea meds, allergy meds (claratin and/or benedryl), and a little antibiotic ointment, though as a matter of fact now they are recommending against using that, IIRC.
Putting a repair kit in backpack(1st aid for bodies and gear, I guess): needle/thread, spare buttons, safety pins, and stick-on nylon patch material (along with some plain nylon that can be used to sew a patch on trousers). It all fits in a film canister (remember those?).
For the record, through the years we have used: bandaids in large numbers. Allergy meds. Ibuprofen in dangerous amounts. The repair kit as well.
Bandannas have many different uses. You can use them as a sling, bandage or part of a splint. The brighter colored ones can also be used as a distress flag if needed. One of them I will keep in a baggy to keep it clean in case it is needed to cover a wound. I've started taking a couple of bandannas with me but mostly for a pre-filter to my water or to cool off with.
I have a small tub of silvadene cream typically for burns. It works pretty great instantly on severe burns. I don't have much left but the stuff is like gold. it's a topical pain-killer. I first discovered it because of my son. He was two years old when he dipped his hand into the ashes from a charcoal barbeque pit, thinking it was sand. He screamed all the way to the hospital. They put the cream on his hand and he was immediately fine. I keep some around ever since.
Ibuprofen, neosporin, bandaids, duct tape, benadryl, & hydrocodone. I carry plenty of IB to get me through every hill climb, and a bad day in case my knees act up. The pain med is mostly for lower back problems. I have 2 hot spots that recur, 1 on each foot, so I tape them before I start and usually redo again in about 4 days. I will sometimes substitute white cloth tape for this purpose. It comes off in the shower after the trip, or eventually at the same time I get home. I normally use the white cloth medical tape on both my pink and ring toes on one foot because they like to mash into each other and wear themselves raw (no fault of my hiking shoes, that's 100% on my daily walkers). Lately, I've been using perforated clear plastic tape with similar results. Both of them I tend to replace daily as they get pretty skunk after a hard day's hike. Something that I carry that I haven't seen anyone mentioned is a blood clotting agent. I bleed easily and if one thing is going to save my life out there after an injury it is probably going to be Celox or Quikclot.
One first aid kit that includes bandaids, sterile gauze, medical tape (around the ibuprofen container), leukotape (kind of like kinesio tape), nonlatex gloves, tick puller, immodium, ibuprofen, several doses of my migraine prescription, Naproxen, benadryl, tincture of benzoin, a blister-specific kit, all my clothes, my sleeping gear, my shelter, my water filter, my stove, my pack stay, my trekking poles, my hydration bladder, and my brain.
First aid training is good. Wilderness specific first aid training is BETTER. Without training the list of useful items gets limited and less useful.
Top (3) items in priority:
And Spare prescription glasses.
My "kit" contains:
Advil or Motrin tablets
Benadryl (pill form)
A few band aids in assorted shapes and sizes
A couple packs of bacitracin or similar
A small roll of 2" elastic sticky tape
Not specific to the kit, but I also carry:
A Victorinox Recruit, which has tweezers.
Several feet of paracord
Some duct tape wrapped around one of my trekking polls
Glass cleaning wipes (alcohol pads)