Adrenaline is also known as the fight-or-flight hormone. It’s released in response to a stressful, exciting, dangerous, or threatening situation.
Adrenaline, also called epinephrine, helps your body react more quickly to a threat. It makes the heart beat faster, increases blood flow to the brain and muscles, and stimulates the body to make sugar to use for fuel. When adrenaline is released suddenly, it’s often referred to as an adrenaline rush.
Adrenaline is a hormone released by your adrenal glands and some neurons.
The adrenal glands are located at the top of each kidney. They are responsible for producing many hormones, including:
The pituitary gland controls the adrenal glands. The adrenal glands are divided into two parts:
- outer glands (adrenal cortex)
- inner glands (adrenal medulla)
The inner glands produce adrenaline.
Keep reading to learn how adrenaline affects the body and how to manage the symptoms of an adrenaline rush.
An adrenaline rush begins in the brain. When you perceive a dangerous or stressful situation, that information is sent to a part of the brain called the amygdala. The amygdala plays a role in emotional processing.
If the amygdala perceives danger, it signals another region of the brain called the hypothalamus. The hypothalamus is the brain’s command center. It communicates with the rest of the body through the sympathetic nervous system.
The hypothalamus transmits a signal through autonomic nerves to the adrenal medulla (inner glands of adrenals). When the adrenal glands receive the signal, they release adrenaline into the bloodstream.
Once in the bloodstream, adrenaline:
- Gives your muscles a boost of energy: Adrenaline does this by binding to receptors on liver cells to break down larger sugar molecules into a smaller, more readily usable sugar called glucose.
- Makes you breathe faster: It binds to receptors on muscle cells in the lungs.
- Increases your heart rate: It stimulates cells of the heart to beat faster.
- Sends blood to your muscles: It triggers the blood vessels to contract and direct blood toward major muscle groups.
- Makes you sweat: It contracts muscle cells below the surface of the skin to stimulate perspiration.
- Stops insulin production: It binds to receptors in the pancreas to stop the production of insulin, a hormone that regulates the amount of glucose in the blood.
A rush of adrenaline is what gives you the ability to dodge out of the way of an oncoming car before you’ve had a chance to even think about it.
These changes happen so fast that you might not even fully process what’s happening.
Although adrenaline has an evolutionary purpose, some people take part in certain activities for the adrenaline rush. Activities that can cause an adrenaline rush include:
- watching a horror movie
- cliff jumping
- bungee jumping
- cage diving with sharks
- zip lining
- white water rafting
Medical causes of adrenaline rush
People may also use adrenaline as a medication. Someone may experience an adrenaline rush, for example, upon receiving an injection of adrenaline for anaphylaxis.
An adrenaline rush is sometimes described as a boost of energy. Other symptoms may include:
- rapid heart rate
- heightened senses
- rapid breathing
- decreased ability to feel pain
- increased strength and performance
- dilated pupils
- feeling jittery or nervous
After the stress or danger is gone, the effect of adrenaline may last up to an hour, depending on the intensity of what’s activating the adrenals.
While the fight-or-flight response is useful when it comes to avoiding a car accident or running away from danger, it can be a problem when activated in response to everyday stress.
A mind full of thoughts, anxiety, and worry can also stimulate your body to release adrenaline and other stress-related hormones like cortisol.
This is especially true at night when you lie in bed. In a quiet, dark room, some people can’t stop focusing on stressors, such as a conflict that happened that day or worrying about what’s going to happen tomorrow.
While your brain perceives this stress, real danger isn’t actually present. So the extra boost of energy you get from the adrenaline rush has no use. This can leave you feeling restless and irritable, making it more difficult to fall asleep.
Adrenaline may also release in response to:
- loud noises
- bright lights
- high temperatures
Watching television before bedtime, using your cellphone or computer, or listening to loud music may contribute to a surge of adrenaline at night.
You can learn techniques to counter your body’s stress response. Experiencing some stress is natural and sometimes even beneficial for your health.
But over time, persistent surges of adrenaline can negatively affect your body. Chronic stress can:
- damage your blood vessels
- increase your blood pressure
- elevate your risk of heart attacks or stroke
- cause anxiety
- cause weight gain
- trigger headaches
- cause insomnia
To help control adrenaline, you’ll need to activate your parasympathetic nervous system, also known as the rest-and-digest system. This is the opposite of the fight-or-flight response. It helps promote equilibrium in the body and allows your body to rest and repair itself.
Try the following to engage the parasympathetic nervous system:
- deep breathing exercises
- yoga or tai chi exercises, which combine movements with deep breathing
- talk with friends or family about stressful situations, so you’re less likely to dwell on them at night; similarly, you can keep a diary of your feelings or thoughts
- eat a balanced diet
- exercise regularly
- limit caffeine and alcohol consumption
- avoid cellphones, bright lights, computers, loud music, and TV right before bedtime
Did you know?
The release of adrenaline from the adrenal medulla naturally decreases with age. Older adults release less adrenaline in stressful and restful situations. Researchers hypothesize that this has to do with depleted autonomic nervous system activity and adrenaline synthesis from aging.
If you have chronic stress or anxiety that prevents you from getting rest at night, consider speaking with a doctor or psychologist. They may suggest different therapy techniques or anti-anxiety medications, such as selective serotonin reuptake inhibitors (SSRIs).
Medical conditions that cause an overproduction of adrenaline are rare but possible. They may include:
- Tumors: A tumor of the adrenal glands can overstimulate the production of adrenaline and cause adrenaline rushes.
- Cushing syndrome: Cushing syndrome is a related disorder that causes weight gain and muscle weakness from long-term exposure to elevated cortisol levels.
- Addison’s disease: Some people are at risk of Addison’s disease if their adrenal glands don’t produce enough hormones.
- Post-traumatic stress disorder (PTSD): For people with PTSD, memories of the trauma may elevate adrenaline levels after the traumatic event.
If you sense an imbalance due to dysregulated adrenal function, consider scheduling an appointment with a doctor to begin the appropriate treatment.
The following are frequently asked questions about adrenaline.
What does an adrenaline rush feel like?
An adrenaline rush
You might recognize these sensations. Imagine you’re driving and someone swerves in front of you, almost colliding with your car. Hopefully, if you’re paying attention, you instinctively jerk the wheel the other way. How you feel after having avoided an accident is how an adrenaline rush feels.
How long does an adrenaline rush last?
How long an adrenaline rush lasts depends on what causes it. If someone plays a prank on you and jumps out from behind a wall, the adrenaline rush is usually momentary and subsides within minutes.
In crisis situations, an adrenaline rush can last longer, often up to an hour. Once the threat disappears, the parasympathetic nervous system attempts to return the body to its nonarousal state.
If the sympathetic nervous system is continually activated from lasting psychological stress, it may have long-term effects on your immune and inflammatory responses.
What happens if adrenaline is high?
The natural response to high adrenaline includes increased heart rate, breathing, and perspiration. If your adrenaline is high, you may not realize you’re in pain because the sympathetic nervous system overrides the pain response.
Can adrenaline cause panic attacks?
Panic attacks occur when the fight-or-flight response triggers with no known cause. They can occur with certain mental health conditions, such as anxiety or PTSD. Adrenaline rushes are indirectly related to these conditions because of the effect stress has on the hypothalamus-pituitary-adrenal (HPA) axis. However, the exact cause of panic attacks is unknown.
An adrenaline rush is a phrase used to describe a rapid hormonal release in the body. When the adrenal glands release adrenaline, the body prepares to protect itself from either real or perceived danger.
If the adrenals produce adrenaline without the threat of danger, an adrenaline rush has the potential to ramp up the sympathetic nervous system and make you feel anxious.
You can generally self-manage an overactive sympathetic nervous system through deep breathing or other stress-reducing activities. However, some people may require medical intervention to help their adrenals return to baseline functioning.