Good idea to notify family and friends in advance to be alert to potential concussions in cyclists. Discuss the risks and symptoms so they'll know what to watch for if we or another cyclist falls.

There's a risk of concussion even without head impact, as a good jolt to the body can make our brains bounce around inside the skull. The risk increases with age as our brains shrink.

It's common to experience a "lucid interval" even with serious internal head injuries but no obvious external injuries. And it's not unusual for folks who've experienced concussions or been unconscious to deny that anything is wrong, and even to refuse treatment or examination. If they become very irritable or angry about medical attention they've almost certainly experienced shock, at a minimum, and possibly a concussion and brain injury (unless the person is always just a jerk!).

Followup physical exams are a good idea over the 48 hours after a potential concussion. And there's no shame in seeking psychological evaluation and counseling or therapy if symptoms of PTSD or unusual changes in behavior occur. Some folks may experience confusion for months afterward, and others may feel irritable, depressed, agitated, etc. Helps to be aware of the symptoms and let others know what to watch for.