Is adrenaline harmful to your body?

Not necessarily. Adrenaline is helpful for you to deal with the daily stress. It's only harmful to you if it is supraphysiologic for prolonged period of time.
Fight or flight. When adrenaline is released, you may have the following symptoms: sweating, palpitations, dilated pupils, dry mouth, constipation, lack of appetite, high blood pressure, anxiety, cold extremities, decreased urine flow, insomnia, dry nose. Excessive adrenaline can be harmful over time.