Coffee is what we love, it is so refreshing and kick starts our morning so well, but there must be something in it that is doing all the magic, and the answer is caffeine, when we drink our first cup, after 10 minutes our blood stream is transporting caffeine to our brain and as caffeine is a stimulant, it modulates the way our neurotransmitter works: neurotransmitters are chemical messenger that helps neuron communicate with each other, because of these electro-chemical signal in our brain we are able to think and carry out our day to day activities, so when our brain comes in contact with it and as it is a psychoactive compound (caffeine) it modulates the operations of neurotransmitters like ( dopamine, histamine etc) and allow them to operate with optimum efficiency.
Caffeine also triggers our sympathetic nervous system ( which is responsible for controlling unconscious activities) and hence activating the flight and fight mode. It stimulates the brain receptors that make us alert and produces more adrenaline (increase in adrenaline level will dilate air passages and blood flow will increase to muscles) hence one outcome can be a sharper vision.
After around 16 minutes of drinking coffee, the caffeine elevates our heart rate, blood pressure by an average of 10 to 15 percent hence showing an increase in cardiovascular activity by increasing the sensitivity of neural pathways so that electrical impulses which are responsible for triggering our cardiovascular system are excited to a higher degree thus making the neural connections more efficient and fast.
After Around 20 minutes caffeine totally kicks in and we feel more energy that is because the caffeine is now regulating your adenosine levels, so this neurotransmitter is related to sleep and tells us when to sleep, so caffeine binds to the brain adenosine receptor and shuts them off and side by side it increases levels of
dopamine and glutamine, that is why we feel so awake.
After few minutes when body began start kicking adrenaline , it will result in elevated mood and our brain becomes more sensitive to serotonin a neurotransmitter which regulates our mood.
After devouring your first cup of coffee , the effect will seem to diminish after 3 hours because the level of caffeine is low and is being metabolized plus the level of adrenaline will drop alongside and hence low level of blood caffeine results in low level of adrenaline secretion as they are in this case directly related to each other, so when you feel that you are getting sober then your brain will ask you to hit another cup to maintain that kick.
coffee in limited amount is fine but in high dosages is not good for your Health, Higher level of dosage can result in acidity, heart issues. stomach issues and substance dependency.