Adrenaline - the alarm hormone

If danger threatens, adrenaline puts the body on alert at lightning speed

The body gets an adrenaline rush not only in direct danger, but also in extreme situations

© Getty Images / Alex Treadway / National Geographic Image Collection

As soon as a person has the feeling that now it's about everything, adrenaline rushes through their veins. The stress hormone quickly binds to certain receptors. It sharpens the senses and releases energy reserves. That prepares us for flight or fight. In the past this was how we managed to escape the saber-toothed tiger, today we may be able to avoid a car at the last moment. Many people want to experience the hormone kick more often. You don't need a bungee jump, a fast sleigh ride does too.

How adrenaline works

  • The hormone floods the body. Adrenaline is produced in the adrenal medulla.
  • The blood pressure rises. Organs such as the brain and muscles are better supplied with blood via the vascular system.
  • The heart pumps faster and more forcefully. The hormone binds to receptors on the heart and thus increases the speed of the heartbeat.
  • Energy is provided. The liver regulates blood sugar levels. Adrenaline increases blood sugar, which fuels muscles and organs.
  • The breath becomes faster. The bronchi widen in the lungs. You can breathe deeper. The blood is enriched with more oxygen.
  • The muscles are tense. All muscles for strength and speed are supplied with more blood. The smooth muscles, on the other hand, like in the intestine, slacken. Digestion is now secondary.
  • The pupils enlarge. This makes the field of view a little larger. This can help to perceive dangers more quickly.
  • The hair stands on end. Adrenaline gives you goose bumps. In animals, this is much more visible when their fur stands on end.

When stress makes you sick

In everyday life, stress is seldom triggered by a physical threat, rather by the diverse demands in family, school or work. That can spice up life. However, constant stress can also become a health problem. Researchers report in the journal Nature Scientific Reports that it is just as clogging for the body as fatty, unhealthy food. Constant stress can also damage the immune system: You feel sick, exhausted, suffer from sleep problems or headaches. This can lead to chronic exhaustion.

Adrenaline in Medicine

Doctors have been treating cardiovascular arrest in an emergency with an adrenaline injection for many years. In the past, the hormone was even injected directly into the pumping organ. Adrenaline makes it beat again and can save lives.

The hormone is also sometimes used in acute gastrointestinal bleeding, for example as a result of a stress-related gastric ulcer. The doctor can inject a diluted adrenaline solution under the bleeding vessel during a gastroscopy. It narrows, the bleeding stops.

A wasp sting or traces of peanut in food can cause life-threatening anaphylactic shock in some people. Affected allergy sufferers usually carry an emergency kit with them, which also includes a pre-filled syringe with adrenaline. Injected into the thigh muscle, the hormone prevents the circulation from breaking down.