• Flushed face.
• Twitching in muscle.
• Gastrointestinal disturbance.
• Rambling thinking or speech.
• Psychomotor agitation.
• Periods of exhaustion.
Caffeine-induced sleep disorder results from over-consumption of caffeine. If a person consumes caffeine immediately before bedtime or regularly throughout the day then the sleep delays, total sleep time reduces, normal stages of sleep later and the sleep quality decreases. High dose of caffeine in late evening sleep onset latency (length of time it takes to go from full wakefulness to sleep).
Excessive caffeine consumption leads to an intoxicated state. Caffeine intoxication presents as excitement, restlessness, agitation, rambling thought, and insomnia. Caffeine taken in the morning can have these signs of intoxication the following night.
The amount of caffeine that is necessary to produce symptoms varies from person to person. Caffeine affects every individual differently. It is observed that consuming caffeine regularly some people do not report any sleep problems.