Epinephrine and norepinephrine are hormones classified as catecholamines. They are produced by the adrenal glands, which are found on top of the kidneys. If you're under physical or emotional stress, the adrenal glands release a surge of these hormones in a "fight or flight" response to help your body deal with any possible danger around you.
Epinephrine
Epinephrine is better known as adrenaline. When you encounter a possible threat, adrenaline starts pumping to help your body respond. It will increase your heart rate, elevate your blood pressure and boost energy supplies. In threatening situations, that surge of epinephrine can save your life, and your hormone levels will drop back to normal once the threat has passed. However, when people are under a lot of constant stress, that fight-or-flight response system doesn't shut down and can potentially lead to problems such as heart disease, trouble sleeping, digestive problems and depression.
Allergies
Epinephrine is commonly used when the body has an extreme reaction to an allergen. People who know they are highly allergic to certain foods, insect bites or medications may carry an epinephrine auto-injector with them. These injectors, which are often referred to by the trade name EpiPen, are used to deliver a quick boost of epinephrine into the system. The single-dose, pre-filled devices are injected into the thigh and are used to relax the muscles in the airways and tighten blood vessels to cope with allergic reactions such as wheezing, shortness of breath, low blood pressure, itching and swelling.
Norepinephrine
Norepinephrine is also known as noradrenaline. It's very similar in composition to epinephrine and in certain cells of the adrenal glands, it can be chemically transformed into epinephrine. Norepinephrine works in the body as a neurotransmitter. It helps transmit signals from one neuron to another neuron or muscle cell. Drugs that are designed to perform like norepinephrine are often used to treat asthma and relax bronchial muscles. People suffering from depression may be prescribed medications that block the absorption of norepinephrine in the brain to help boost their moods.
Testing
Doctors can determine the levels of catecholamines in the body in two ways---blood and urine tests. Though blood tests may be used, epinephrine and norepinephrine levels are more commonly determined though urine tests. Patients are often advised before testing to try to avoid stressful situations and vigorous exercise and to refrain from eating foods such as coffee, tea, chocolate, cocoa, bananas, citrus fruits and vanilla, all of which can interfere with test results.
