How caffeine can affect your stress level. How does it affect your cardiorespiratory system?

Caffeine stimulates your nervous system, which means too much can lead to a rapid heartbeat and increase in blood pressure. It can also irritate your digestive system. Additionally, excess caffeine can interfere with sleep and trigger dehydration, which can zap energy and cause headaches.

Caffeine = stimulant. So it adds to physiological arousal that stress can produce. It will increase heart rate, alertness, and insomnia in some people. It can decrease fatigue and improve concentration. If you have high stress or anxiety, caffeine would not be recommended.