Concussed?

This past weekend I took an 8 hr round trip bus ride just to suffer bodily injury (and to enjoy the company of my trip partner). Long story short, I went snowboarding, or should I say ice-boarding. The weather conditions were ridiculously cold and the majority of the mountain was pure ice, or ice chunks. It wasn't the most fun I've ever had boarding, but it was definitely an experience to remember. (including the near-hitchhiking to base camp at the end of the day)

Anyway, at one point during the day, I fell backwards and slammed my head into the ground pretty hard. It was enough to daze me for a few minutes. At the time, I just felt like my skull hurt, but nothing serious. However, for the following couple of days I felt like my head wasn't quite right whenever I took a heavy step, like stepping off of a curb. Made me wonder if I had suffered more of an injury than I initially thought. Then last night, I was having dinner when I suddenly started to get a headache and felt nauseous. I hadn't really eaten anything yet so I doubt it was the food. Plus my friend had ordered the same dish and was enjoying it immensely without side effects. I had to cut dinner short and rushed home in a cab. Just in time. It wasn't pretty. I haven't gotten that sick without alcohol involved in... well, I don't know that I've ever been sick without there being alcohol involved. I ended up going to sleep to try and get over the nausea and headache. I woke up this morning, still suffering the headache.

This experience prompted me to do some research on concussions. Here is some of what I found:

The signs and symptoms of a concussion can be subtle and may not appear immediately. Symptoms can last for days, weeks or longer.

Delayed signs and symptoms may include:

Irritability (definitely, but might be a result of incompetent co-workers)
Headaches (check)
Depression (possibly, but may be for other reasons)
Sleep disturbances, including insomnia or difficulty waking (check, but may be for other reasons)
Fatigue (always)
Poor concentration (check, but may be for other reasons)
Getting lost or becoming easily confused (sometimes)
Stiff neck (check)
Severe headache (check)
Repeated vomiting (not repeated... yet)

Anyway, I'm sure it's nothing. Just the overreactive hypochondriac in me. Just thought I'd share some research.