Off the top of my head, here are some of the things you should have on your card. If you have additions or changes to suggest, please leave them in the comments! Note: I did not include insurance information as I keep mine between my ID and my insurance card.
- Phone Number,
- Emergency contact name and numbers,
- Current doctors' names and phone numbers (include specialists you currently see),
- Medications you take and dosages -- both Rx and OTC,
- Equipment you use and implants you have,
- Any tools you may need to communicate, and
- Conditions -- both diagnosed and suspected.
Again, you can make your own if you want, ask at your doctors' offices or pharmacy, or you can look online. I found a service that offers both free cards and ones you can buy here. This site has you fill out the information and puts it in a card you can print out.
Additional solid advice on emergency identification can be found here. I generated over five million search results on Google using "medical emergency card."
Having a card like this is not only handy in emergencies, but also useful when you are filling out the dreaded new patient forms at an unfamiliar doctor's office. It will not keep you from needing to go over the information at, say, an emergency room visit, as they will sometimes discuss it with you anyway to see how you are doing cognitively.