Adrenaline is a vital hormone naturally produced by your body in the adrenal glands. Often referred to as epinephrine, it plays a crucial role in your body’s rapid response to stressful, exciting, or dangerous situations. This response is widely known as the ‘fight or flight’ response, preparing you to either confront or escape a perceived threat. Beyond its natural function, adrenaline is also a critical medication used in emergencies, most notably in cases of severe allergic reactions like anaphylaxis.
Decoding Adrenaline: The Fight or Flight Hormone
Adrenaline, or epinephrine, is a hormone and neurotransmitter. When you encounter a stressful or exciting situation, your brain swiftly sends signals to your adrenal glands. These glands, located atop your kidneys, then release adrenaline into your bloodstream. This rapid release triggers a cascade of physiological changes designed to equip you to deal with the immediate challenge. The effects of adrenaline are felt quickly, typically within minutes of its release.
Once the stressful event subsides, the adrenal glands cease adrenaline production, and the hormone’s effects gradually diminish. However, you might continue to experience lingering effects like trembling, a rapid heartbeat, or paleness for up to 20 minutes as your body returns to its normal state. It’s important to remember that outside of Australia, adrenaline is commonly known as epinephrine, so you may encounter this term in medical contexts or literature.
The Powerful Effects of Adrenaline on Your Body
Adrenaline orchestrates a series of powerful changes throughout your body to optimize your response to stress. It acts swiftly to:
- Elevate Heart Rate: Adrenaline increases your heart rate, pumping blood more rapidly to deliver oxygen and nutrients to your vital organs and muscles.
- Enhance Lung Function: It improves breathing efficiency by dilating the airways, allowing you to take in more oxygen.
- Redistribute Blood Flow: Blood vessels are redirected to send more blood to the brain and skeletal muscles, essential for quick thinking and physical exertion.
- Increase Blood Pressure: Adrenaline raises blood pressure to ensure efficient blood circulation throughout the body.
- Boost Brain Alertness: It sharpens your mental focus and alertness, enabling you to react quickly and decisively.
- Elevate Blood Sugar: Adrenaline triggers the release of glucose (sugar) into the bloodstream, providing a readily available energy source for your muscles and brain.
- Pupil Dilation: Your pupils widen to enhance vision and allow more light to enter your eyes, improving awareness of your surroundings.
- Increased Sweating: Sweating helps to cool your body down as metabolic activity increases.
- Pain Reduction: Adrenaline can temporarily reduce the sensation of pain, allowing you to continue functioning even if injured during a stressful situation.
These combined effects are temporary but crucial, enabling peak physical and mental performance when facing a perceived threat or challenge.
Adrenaline as a Medicine: A Lifesaver in Emergencies
Beyond its natural role, adrenaline is a life-saving medication, particularly in emergency situations. Its primary medical application is in the treatment of severe allergic reactions, known as anaphylaxis. It is also used in various forms during medical emergencies such as:
- Anaphylaxis: Adrenaline is the first-line treatment for anaphylaxis, a severe and potentially life-threatening allergic reaction.
- Cardiac Arrest: Adrenaline injections can be administered during cardiac arrest to stimulate heart function.
- Croup: In severe cases of croup, adrenaline can help to reduce airway swelling and improve breathing.
- Asthma: While not a primary treatment for asthma, adrenaline can be used in severe asthma attacks to help open up airways.
For individuals at risk of anaphylaxis due to known allergies, adrenaline autoinjectors like EpiPen or Anapen are prescribed. These devices are designed for self-administration or administration by a trained individual in emergency situations. Learning how to use an adrenaline autoinjector is crucial for anyone at risk of anaphylaxis.
How Adrenaline Autoinjectors Work to Combat Anaphylaxis
Adrenaline works rapidly to reverse the life-threatening symptoms of anaphylaxis. It achieves this by:
- Reducing Throat Swelling: Adrenaline constricts blood vessels and reduces fluid leakage, which helps to alleviate swelling in the throat and upper airways, making breathing easier.
- Opening Airways: It relaxes the muscles around the airways in the lungs, widening them and improving airflow.
- Preventing Blood Pressure Drop: Adrenaline helps to raise blood pressure, counteracting the dangerous drop in blood pressure that can occur during anaphylaxis.
Adrenaline autoinjectors are designed to deliver a measured dose of adrenaline into the large muscle of the outer thigh. If symptoms do not improve within 5 minutes after the first injection, a second dose from a new autoinjector should be administered. Crucially, even if you feel better after an adrenaline injection, it is vital to seek immediate medical attention at a hospital. Hospital doctors will monitor you for several hours to ensure the anaphylactic reaction is fully resolved and to manage any potential rebound symptoms.
Seek Immediate Medical Help: Recognize Anaphylaxis Symptoms
If you or someone around you experiences any of the following symptoms, and an adrenaline autoinjector is available, use it immediately, and then call emergency services (911 in the US, 999 in the UK, 000 in Australia) for an ambulance:
- Difficulty or noisy breathing (wheezing, stridor)
- Sudden, persistent coughing
- Trouble speaking or hoarse voice
- Dizziness or collapse
- Swelling of the tongue or lips
- Tightness in the throat
Asthma and Allergy: A Critical Overlap
Asthma, food allergies, and anaphylaxis frequently co-exist. Having asthma increases the risk of anaphylaxis in allergic individuals. Therefore, if you have both asthma and allergies, your doctor may prescribe an adrenaline autoinjector as a precautionary measure. In situations where someone with asthma experiences sudden breathing difficulties and also has a known allergy:
- Administer Adrenaline First: Use the adrenaline autoinjector immediately.
- Use Asthma Reliever: Administer their regular asthma reliever medication.
- Call Emergency Services: If breathing remains difficult, call emergency services immediately.
Always adhere to your personal Anaphylaxis Action Plan and then apply asthma first aid protocols, followed by calling emergency services if needed.
The Downsides of Too Much Adrenaline
While adrenaline is essential for survival, excessive levels can be detrimental to your health. Symptoms of having too much adrenaline can include:
- Dizziness
- Blurred vision or other visual disturbances
- Heart palpitations or a racing heart
- Irritability and feeling on edge
- Difficulty sleeping or insomnia
In rare cases, medical conditions such as adrenal gland tumors (pheochromocytoma) can cause the overproduction of adrenaline. Over time, chronically elevated adrenaline levels can contribute to serious health issues, such as:
- High blood pressure (hypertension)
- Unexplained weight loss
- Anxiety disorders
- Increased risk of heart attack and stroke
Adrenaline Deficiency: A Rare Condition
Having too little adrenaline is uncommon. However, if your body doesn’t produce enough adrenaline, your ability to respond effectively to stressful situations would be compromised.
Strategies for Managing Adrenaline Levels
Elevated adrenaline levels are often linked to the body’s stress response. If you suspect that stress is contributing to high adrenaline levels, adopting healthy stress management techniques can be beneficial. These strategies may include:
- Regular exercise
- Mindfulness and meditation practices
- Adequate sleep
- Engaging in relaxing hobbies
- Seeking support from friends, family, or a therapist
When to Consult Your Doctor
If you have known allergies, you are potentially at risk of anaphylaxis and should discuss developing an Anaphylaxis Action Plan with your doctor. If you are deemed at risk, your doctor will prescribe an adrenaline autoinjector. The dosage of adrenaline autoinjectors is prescribed based on age and weight. In Australia and New Zealand, autoinjectors are available in the following doses:
- 150 microgram adrenaline: For children weighing 7.5 to 20kg.
- 300 microgram adrenaline: For adults and children over 20kg.
- 300 or 500 microgram adrenaline: For adults and children over 12 years and 50kg.
It’s crucial to have regular check-ups with your doctor to review your allergy management plan and ensure your adrenaline prescription is up-to-date.
Resources and Support
For comprehensive information on adrenaline autoinjectors, including instructional videos on their use, please visit the ASCIA (Australasian Society of Clinical Immunology and Allergy) website: https://www.allergy.org.au/hp/anaphylaxis.
For health advice and support, you can also contact the healthdirect helpline at 1800 022 222 (NURSE-ON-CALL in Victoria), where registered nurses are available 24/7.
