Headache – (often described as being gradual in development and diffuse, and sometimes throbbing and severe) Fatigue -- (e.g., fatigue, tiredness, lethargy, sluggishness) Sleepiness/drowsiness -- (e.g., sleepy, drowsy, yawning) Difficulty concentrating -- (e.g., muzzy) Work difficulty -- (e.g., decreased motivation for tasks/work) Irritability -- (e.g., irritable, cross, miserable, decreased well-being/contentedness) Depression -- (e.g., depressed mood) Anxiety -- (e.g., anxious, nervous) Flu-like symptoms -- (e.g., nausea/vomiting, muscle aches/stiffness, hot and cold spells, heavy feelings in arms or legs) Impairment in psychomotor, vigilance and cognitive performances
I've cut back my Red Bull intake and have been experiencing this of late. I thought I was getting sick or had mono, but I think it's probably just caffeine.
I just popped open a Red Bull now and I'm feeling better already. That's how you build real billion dollar companies: get people physically addicted.