The body secretes hormones such as adrenaline, thyroid hormones and dopamine that cause the body to become excited. They can maintain normal body functions and produce stress responses. 1. Adrenaline: adrenaline is secreted by the adrenal glands of the human body, which is important for the maintenance of vital signs and normal physiological activities such as heartbeat, blood pressure, body temperature, etc. When the body encounters a stimulus, adrenaline can be secreted to increase the heart rate, respiratory acceleration, and vasodilatation of important organs, which can play a role in the emergency protection of the body. 2. Thyroid hormone: thyroid hormone is secreted by the thyroid gland, which is important for maintaining normal metabolism. When thyroid hormone increases, high metabolic symptoms can occur (such as panic, fatigue, fear of heat, hyperphagia, etc.), and when it decreases, low metabolic symptoms can occur (such as weight gain, drowsiness, memory loss, etc.). 3. Dopamine: Dopamine is produced by the brain and the adrenal medulla. Dopamine, as a neurotransmitter, transmits excitement and happy emotions, and is associated with a sense of pleasure. When acting on the cardiovascular system it can have a positive effect on the heart. Hormones in the human body is in a relatively stable dynamic balance, too much or too little are not conducive to human health, if there are abnormalities, it is recommended to consult a doctor to adjust the cause of treatment.