Adrenaline: Symptoms, Uses and Effects on Human Body

Posted on Updated on 26 September, 2017


The adrenal glands and certain neurons in a human body produce a hormone called Adrenaline or Epinephrine. It takes part in the critical responses of the sympathetic nervous system. It increases the blood flow to muscles that helps react faster. Besides, it also influences, pupil dilation, blood sugar and functioning of hear. Adrenaline manages to do this via binding beta and alpha receptors.  Usually, such situations are dangerous or frustrating. One can also call acute stress response. It is an evolutionary adaption of the human body that helps it adapt or adjust in such extreme situations.

Brief About Adrenaline Uses in Medication

There are many treatments for various diseases that include the use of Adrenaline. Primarily, they cardiac arrest, casual bleeding, and anaphylaxis. Also for treating croup, the doctor uses inhaled Adrenaline.  Moreover, it can treat asthma even when other treatments have failed. There are many ways through which doctors inject this hormone into the body of patients. Usually, they are through injections and inhalation.

It has some side effects as well. Now, this includes sweating, jerkiness, and nervousness.  Besides, the patient may also experience high blood pressure and a fast heart rate. Sometimes, they may even experience abnormal heartbeats. There is not much known about its side effects on pregnant or breastfeeding women. As there are no any life-threatening cases occurred due to its use, so, people consider it safe for them.

When it Gets Secreted?

There are many times a person unknowingly has Adrenaline rush in his body. It happens when you are driving your car at a constant speed and, the car in front stops suddenly causing you to press the brakes instantly. You will experience heavy breathing, sweating, and fast heartbeats afterward. The blood pressure will rise incredibly. Also, the heart will be pumping hard and fast. Few other examples of incidents that may have brought Adrenaline rush into your body would be, if an angry dog has ever chased you, if you have been in street fight, if you have been a driving slow in a fast lane, etc.  These were some of the tragic incidents causing Adrenaline rush.

However, the adrenaline rush is not limited to tragic incidents. It can also happen when good things happen in your life causing you to experience an extreme sense of joy. These good incidents can be winning a lottery, getting your dream job, in being victorious in a big game. You may even experience it when your love of the life accepts your marriage proposal.

Besides, an intense or brief workout session can also entice the adrenaline rush into your body. Perhaps, gyms are the best place to see the guys with an adrenaline rush.

Adrenaline Effects on Human Body

The medulla of adrenal glands located right above the kidney in a human body secretes this hormone called Adrenaline. It is a part of an automatic nervous system also known as the reflex system. It also secretes the hormone that makes us feel good such as dopamine, norepinephrine, and catecholamine.

The adrenals are responsible for around seven percent Norepinephrine circulation. It spills over neurotransmission with minor effects as a hormone. The medicinal intake of Adrenaline motivates various adrenoceptors of the sympathetic nervous system. Besides, sympathetic nerve receptors are known as adrenergic due to its receptiveness to this hormone. It was Cannon who introduced the concept of sympathetic system and adrenal medulla assisting the flight, fight and fright response.  Overall, Adrenaline has various effects on human body. Some of them are as follows:

During Workouts or Exercise

Workouts are one of the physiological stimuli for the secretion of this hormone. The first demonstration of this fact was when the denervated pupil of cat got examined. Later, when urine samples and other biological assessments confirmed this fact.

During workouts, the epinephrine blood concentration rises slightly. Usually, it upsurges from the increased secretion of the adrenal medulla and slightly from decreased metabolism. It is due to the reduced hepatic blood flow. The infusion of Adrenaline controls human airway hyper-reactivity significantly to provoked the effects of inhaled histamine.

In the year 1887, Grossman demonstrated the link between lungs and sympathetic system.  He demonstrated that the cardiac accelerator nerves stimulation reverses muscarine induced airway contraction. Besides, he also demonstrated that lungs have no direct innervation with the sympathetic system. Exercise encourages progressive airway dilation in common people. It correlates with the workload. Even the beta blockade doesn’t prevent it.

Emotional Effects

All the emotional responses that are autonomic come with a behavior component. The hormonal component is responsible for every emotional response. It includes the secretion of Adrenaline during stressful conditions. Usually, the body makes it during fear.

There was even an experiment carried out in which people were injected with Adrenaline and were to watch a horror movie. However, they showed more negative facial expressions than positive facial expressions in that experiment. Some even showed intense fear while watching the movies. They developed more intensity of negative memories. The outcomes of this experiment denote the link between Adrenaline and the negative feelings. So, negative feelings may arise when levels are high. Some of the physiological sympathetic responses during such conditions are knee shaking and increased heartbeat rate.

Apart from the feeling of fear, the researchers don’t find the relations of other emotions with Adrenaline. In the same experiment, the participants did not show any significant fun in an enjoyable movie. Besides, they also didn’t express annoyance to an anger movie. Scientists found same results in a similar experiment on rodents. Hence, we can say that Adrenaline does have a role in supporting some emotional behavior which includes the fear expression.

Adrenaline Effects on Memory

In many studies, the researchers discovered that adrenergic hormones like Adrenaline degrade the long-term memory associated with that event. In an emotionally stressful event that causes the release of Adrenaline can moderate memory consolidation of the events.  The degree of arousal is also associated with the starting coding. It has been proven that this hormone plays a role in fear memory and long-term stress adaptation. This hormone can also raise the arousal and fear memory under specific pathological conditions. Now, this includes conditions like post-traumatic stress disorder.

Different studies have also discovered the recognition memory which involves Adrenaline. It doesn’t willingly disturb the blood-brain barrier. In animal as well as human beings, the adrenaline controls memory alliance for emotionally arousing jobs.

Effects on Various Organs

It has a great impact on many vital organs inside a human body. Some of the organs and adrenaline’s effects on them are as follows:


The Adrenaline influence the adrenergic receptors on cells via the heart tissue.  These receptors forward the critical messages to a particular protein known as G-protein. Afterward, this protein affects other things inside the cell, which initiates a cascading alert effect. The final results of this processes are the increase in heartbeats, conduction across AV node, and contractility.


The Adrenaline affect the lungs significantly. This hormone causes smooth muscle to relax, and as the lungs have smooth Muscle, so, it influences them as well. Now, this speed up the respiration process. Scientists found that the respiratory rate got increased. Also, bronchodilation also occurs due to this hormone. In fact, an experiment on rats also proved these effects.


Glucagon along with Adrenaline is the cause for the collapse of glycogen in liver cells. In human beings, Glycogen is a kind of energy storage. It binds to a receptor on the outer of a liver cell that leads to a conformational change. Now, this allows G protein to bind. In the Complex, ATP and adenylate cyclase can bind subsequently. Overall, it primarily stimulates glycogenolysis in the liver.

Some of the other systemic processes that it effects are vasodilation, Vasoconstriction, Muscle contraction, and lipolysis triggers. Besides, it influences almost all body tissues. However, the results vary on the different types of tissues. For example, the smooth muscle gets relaxed but contracts that line most arterioles.

How the Body Controls Adrenaline?

Usually, the body produces Adrenaline as a response to the stressful events, so that the body gets prepared for the fight or flight response. Such events trigger the nerved connected to the adrenal glands. Now, this starts the release of this hormone from the glands. Eventually, the level of adrenaline gets increased in the blood. The releasing process happens instantly. In fact, it takes around two to three minutes for the body to produce this hormone after encountering an extremely stressful event. After the end of such situation, the impulse of nerves that triggered adrenal glands gets lowered. Eventually, this causes the adrenal glands to stop producing and releasing adrenaline.

Apart from adrenaline, the stressful events also arouse the pituitary gland to release adrenocorticotropic hormone. Now, this encourages the production of cortisol hormone, which is a steroid hormone. The cortex of the adrenal glands is responsible for the production. It has a huge impact in modifying the body’s metabolism. It raises the plasma glucose under longer-term conditions.

Overproduction of Adrenaline by the Body

It is a rare phenomenon of a body overproducing adrenaline. However, there exist some cases where an individual’s body was overproducing this hormone. It can cause a variety of side-effects. It can cause a rare tumor in the adrenal medulla. Besides, the individual will have rapid heart rates, anxiety, high blood pressure, excess sweating, palpitations, and weight loss.

Underproduction of Adrenaline by the Body

The underproduction of this hormone is also a rare phenomenon. However, there are some people whose body has produces too little adrenaline. Primarily, the body would be incapable of taking a quick action or response in an extremely stressful condition. It can be dangerous in a life-threatening situation.

Superhuman Strength

Adrenaline may provide superhuman strength to an individual during the time of crisis. There are many examples across the world where people have demonstrated superhuman strength at the crisis times. However, there is no any significant proof of this fact. Also, doctors across the world dismiss this fact. The supporting evidence of this fact is rare as well as inconclusive. A lot of people believe that during excited delirium, it may give superhuman strength to the individual.

Adrenaline Junkie

Nowadays, the concept of adrenaline junkie has developed in the society. They are the people who engage themselves in sensation-seeking behavior via increasing the adrenaline level of the body unnaturally. However, they don’t care about the physical, legal, social risk regarding that. These activities are extreme sports, unnatural sex, and even crimes. In many sports, the authorities have banned it as well. It increases alertness and plays a major in memory consolidation.

Adrenaline Drug

In many cases, the doctors recommend adrenaline drug to boost this hormone in a patient’s body. It helps in opening lungs airways and narrowing blood vessels. It can be useful in wheezing, low blood pressure, hives, skin itching, etc. Besides, it is beneficial for treating allergic reactions of other drugs, insect stings, and foods.

Side Effects of Adrenaline Drug

Just like most of the drugs, Adrenaline drug has side effects as well. They are headaches, fear, nervousness, anxiety, excess sweating, palpitations, nausea, pale skin, vomiting, dizziness, tremors, weakness, breathing difficulty, tremors, etc.  If you feel any serious side effects in your first injection, then you must consult your doctor before taking the second dosage of it.

Symptoms of Adrenaline Rush in Your Body

  • An adrenaline rush may increase your strength incredibly.
  • It may stop the feeling of pain for some time even if your body is suffering from a severe injury.
  • You sense like vision, touch, hearing, and other might get dramatically heightened.
  • It may incredibly boost your energy level.

An adrenaline rush may increase your heart and breathing rate.