Not sure if I'm posting in the right forum for this. My reaction time (most notably in athletic activities) has decreased significantly lately, to the point that family members and a coach are worried. What could possibly be causing this? I've been getting the same amount of sleep as ever. I have adrenal problems and nutrient deficiencies. I occasionally experience presyncope usually upon standing or sitting up but also sometimes at random, and there has been an increase in the number of occurrences of this recently. That may not be related at all, but I'll let you all decide. The most common causes for slowed reaction time I've found are lack of sleep (no change), hypothyroidism (my thyroid is not perfect but certainly not bad), and Parkinson's (I'm only 21).