For me, a crash is when i get really exhausted and am near unfunctional. A crash to me means that my body is crying out to be bedridden. My body says "No more, you are driving on empty, anymore and i will simply turn off." That's a scary feeling and thought. I hate it, but i've learned to just go and lay down. When you are borderline crashing or you do indeed crash it's a good idea to have family and friends help you out. i always carry my Cell Phone when i feel vulnerable in case my wife needs to come and save me last minute. A crash to me is bad news. it usually means i have taken a step backwards in my recovery, but have hope because there are more steps being taken forward. We usually don't believe or notice too much progress because of the foggy thinking, but when you crash, you begin to realize how good you actually had it before you crashed. i am grateful now when i feel even a 4 out of 10. Even with mild brain fog, mild headache, threatning fatigue, i still am grateful to God for my day because i think that at least i'm walking and not crashing. Crashing usually happens because we push our limits.