Hormones called catecholamines act as modulators of our stress response, also known as the “fight-or-flight response.” When they circulate through the body at higher levels, this can have effects including increasing heart rate, blood pressure, breathing rate, muscle strength and mental alertness.
While these are essential hormones that play many important roles and allow us to function, abnormally high levels can point to an underlying health problem, possibly due to chronic stress.
Doctors test levels of catecholamines in order to look for signs of certain rare tumors, as well as other problems, such as high blood pressure, headaches or enzyme deficiencies.
What Are Catecholamines?
Where are catecholamines produced? They are made by the adrenal glands, which are located at the top of the kidneys, and also the brain and nerve tissue.
They are released into the blood when someone is under stress and can also be affected if you have certain health conditions, by your diet and by some medications.
Here’s an overview of how catecholamines are synthesized:
- The adrenal medulla (the inner part of an adrenal gland) is considered the most functionally significant area of catecholamine production in the body.
- Tyrosine undergoes hydroxylation via tyrosine hydroxylase to form DOPA. DOPA is then turned into dopamine.
- Dopamine can be secreted into the bloodstream or turned into norepinephrine via the process of hydroxylation.
- Norepinephrine can also be secreted into the bloodstream or further modified to create epinephrine (adrenaline).
- In order to maintain normal catecholamine levels, these hormones are usually broken down and then eliminated via the urine with help from the kidneys.
Roles and Benefits
What is the function of catecholamines? Research shows that catecholamines act both as neurotransmitters and hormones.
They play a major role in helping maintain homeostasis through actions of the autonomic nervous system.
What are the two types of catecholamines?
Dopamine is chemically classified as a catecholamine, but dopamine acts somewhat differently than the other major catecholamines, norepinephrine and epinephrine. Most of our dopamine is produced in the brain, while most norepinephrine and epinephrine is produced in the adrenals.
Catecholamines work by activating adrenergic receptors that are located throughout the body in smooth muscle and adipose (fat) tissue.
Below are some of the roles and functions of catecholamines:
- Activate the “fight or flight” response of the sympathetic nervous system.
- Regulate blood pressure by contracting the smooth muscle in the vasculature.
- Help control musculoskeletal actions, including contractility of cardiac muscle.
- Help control relaxation/contraction of smooth muscles in the gastrointestinal tract, urinary tract and bronchioles.
- Contract pupils in the eyes.
- Modulate metabolism to increase blood glucose levels by stimulating glycogenolysis in the liver.
- Help control glucagon secretion and insulin secretion from the pancreas and lipolysis in adipose tissue.
- Inhibit release of mediators from mast cells.
In terms of keeping us healthy, what are catecholamines beneficial for? They help us respond to stress, which comes in many forms.
“Stress” describes both physical and emotional stressors, some of which are considered “bad stressors.” Others are called “good stressors” (or eustress).
Catecholamines are also needed to keep us mentally alert, for motivation, and to control metabolism and moods.
High vs. Normal Levels
What causes catecholamines to be high? Levels in the blood (or serum concentration) are mostly determined by someone’s level of stress, underlying health conditions, diet and exercise, and if he or she uses medications.
Even the temperature outside, someone’s position and blood sugar level/the last time someone ate can impact levels.
Levels of the amino acid called tyrosine also affect catecholamine production, as explained above.
Catecholamines are sometimes referred to as “stress chemicals” because levels are higher when someone experiences lots of stress. Abnormal levels (too high or low) may be caused by health conditions such as:
- Acute/short-term anxiety
- Chronic/severe stress
- Illnesses/trauma, such as injuries, whole body burns or infections
- Development of a tumors, which can be cancerous or noncancerous. A rare type of tumor that may be the cause is called a pheochromocytoma. A type of cancer that affects the nervous system called neuroblastoma can also affect levels.
- Baroreflex failure (a rare disorder involving blood pressure changes)
- Certain enzyme deficiencies
- Menkes syndrome (a disorder that affects copper levels in the body)
- Use of blood pressure medications, MAOIS, certain antidepressants, caffeine and other drugs
There are even some foods that can increase catecholamine levels, such as:
- Coffee and tea (which contain caffeine)
- Citrus fruits
High catecholamines symptoms can include:
- High blood pressure and rapid heartbeat
- Excessive sweating
- Severe headaches
- Weight loss
- Anxiety symptoms
To be considered “normal,” levels of catecholamine hormones in adults should fall within this range (check with your provider/laboratory since some tests use different ranges, including for children):
- Dopamine: 65 to 400 micrograms (mcg)/40 to 400.0 mcg for those older than 4
- Epinephrine: 0.5 to 20 mcg/0.0 to 20.0 mcg for those younger than 16
- Metanephrine: 24 to 96 mcg (or 140 to 785 mcg)
- Norepinephrine: 15 to 80 mcg/4 to 80.0 mcg for those younger than 10
- Normetanephrine: 75 to 375 mcg
- Total urine catecholamines: 14 to 110 mcg
- VMA: 2 to 7 milligrams (mg)
A doctor might recommend a catecholamines test to determine if a patient’s symptoms are tied to high or low levels. Health conditions that are linked to abnormal levels include:
- high blood pressure
- severe headaches
- fast heartbeat
- tumors on the adrenal glands
Screening tests can look for increased levels of urinary or plasma metanephrines, which result from the normal breakdown product of catecholamines.
This type of test often involves measuring levels of hormones in the blood over a 24-hour period. Depending on the results, other tests might also be needed to confirm a diagnosis, such as a CT, MRI or PET imaging test to view the adrenals.
Be sure to follow your doctor’s instructions carefully, since a number of factors can impact your test results.
- What are catecholamines? They are hormones that are released in response to stress and that help us maintain homeostasis.
- Examples of catecholamines include dopamine, norepinephrine and epinephrine.
- Their roles/function include acting as modulators of the stress response, also known as the fight-or-flight response. They work by increasing heart rate, breathing rate, muscle function, etc.
- A catecholamine test can be used to determine why someone is experiencing symptoms such as high blood pressure, excessive sweating, headaches, fast heartbeats (palpitations) and tremors.
- Potential reasons someone may have higher levels than normal can include acute or chronic stress, illnesses/trauma such as injuries, whole body burns or infections, surgery, use of blood pressure medications, or rarely due to a tumor.