4 in total. One suffered in bicycle accident during road race in North County SD. By far the worst was when I passed out while shopping (had flu and was majorly dehydrated) and cracked my head on the concrete floor. Halo skull fracture. Off to local trauma center in the ambulance for a 10 day stay. 2 months off work. Most recent was when I was moving some upper cabinets in my garage. Removed what I 'thought' were all the mounting screws but cabinet was stubborn. I pulled and pulled until it CAME. Saw stars and dark but managed to stay on my feet. Lots of blood with that one.