What is norepinephrine?


Norepinephrine is a central nervous system (CNS) chemical messenger and a stress hormone secreted by the adrenal glands. It regulates numerous internal functions that keep your brain and body running efficiently.

This article explains many of the important functions of norepinephrine or NE. It also includes information on the causes of abnormal norepinephrine levels and related conditions, as well as ways to keep NE levels balanced.

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Where is norepinephrine produced?

The brain and spinal cord make up your CNS. It is, so to speak, the main processing center of your body, where external and internal information is interpreted. It controls many things, including your daily movements, body functions, feelings, thoughts, hunger levels, and more.

The central nervous system can communicate with your body through nerve cells called neurons. It has about 86 billion of them, and its job is to transmit signals from your brain to your muscles and cells, which is why they are also called chemical messengers or neurotransmitters.

Among these are specialized neurons located in the trunk and spinal cord called postganglionic neurons. These are neurons that release norepinephrine.

Once released, the NE travels to its target nerve, binds to the nerve receptor, and directs it into action. This directive could be to go to sleep or wake up, be more focused, feel happy, and more.

Norepinephrine is also produced in the inner part of the adrenal gland called the adrenal medulla. In this case, NE is generated by the sympathetic nervous system (SNS), the driving force behind your fight or flight response.

When the body is stressed, its social network signals the adrenal glands to release norepinephrine. NE then travels through your bloodstream and, as a hormone, initiates a stress response that allows you to quickly mobilize your body and brain so you can defend yourself.

What norepinephrine does

Norepinephrine is at the center of many functions that help maintain your health. At times, you may be very aware that it is flowing through your veins; think of sweaty palms when you're nervous, or fast heartbeats when you're scared. In other cases, you may not even know it is there.

Here's a look at what norepinephrine does for you.

Maintains stable biorhythms

Biorhythms are body cycles associated with your physical, emotional, and mental health. A small amount of norepinephrine always circulates in your body to keep these cycles stable.

The biorhythms that NE helps regulate include:

  • Blood flow to skeletal muscles
  • Skeletal muscle contraction that allows it to move.
  • Blood glucose levels
  • Mood stability

Supports organ function

In general, EN affects many organs throughout the body, including:

  • Eyes : NE increases tear production and dilates the pupils in response to light and emotion.
  • Kidneys : NE causes the kidneys to secrete renin , which regulates the balance of salt and water.
  • Pancreas : NE causes your pancreas to secrete glucagon so your liver can make more glucose.
  • Lymphoid organs: NE stimulates organs such as the spleen , thymus , and lymph nodes to help your immune system fight infection.
  • Gut : NE reduces blood flow to the intestines and slows down the digestive system.

Protect from damage

Norepinephrine allows your stress response to protect you from danger, both real and perceived.

Take, for example, exposure to extreme cold. Your body knows that most of the heat is lost through the skin. To stay healthy, you need to conserve all the heat you have.

To do this, the nerves secrete norepinephrine, which then binds to cell receptors in the skin. Because NE constricts the blood vessels, it reduces blood flow to the skin, making it difficult to dissipate heat.

Other types of threats elicit different responses. When your brain perceives an external threat, such as someone stalking you, a part of the brain known as the hypothalamus energizes your social networks. This forces the adrenal glands to pump norepinephrine.

As part of this response, norepinephrine increases:

  • Surveillance
  • Attention
  • Pain tolerance
  • Reaction time
  • Breathing frequency
  • Extract memory

Digestion and the immune system are considered secondary functions during this period. NE turns them off so more power can be directed to the functions you need for your safety.

Along with adrenaline , norepinephrine also increases heart rate and blood pressure, and stimulates the liver to produce more sugar (glucose) in the blood so that your body can use it for energy.

This reaction can occur in situations that simply make you feel nervous or nervous, but are not real threats (such as a tense meeting or an argument with a partner).


Small amounts of norepinephrine constantly pass through the central nervous system, regulating basic bodily functions. When faced with stress or danger, your hypothalamus alerts your brain to pump more norepinephrine to prepare for action.

Norepinephrine-related conditions

Healthcare providers generally do not monitor norepinephrine levels during routine checkups. They may suspect a change in NE level based on your symptoms, in which case they may order a urine or blood test for investigation.

The normal range for norepinephrine for a blood test is 70 to 1700 picograms per milliliter (pg / ml). There are many explanations why your NE levels may be higher or lower, from rare tumors to anxiety and stress.

Your healthcare provider may not immediately know the reason for the change in NE level. In this case, they will need to investigate further by conducting additional tests based on your symptoms.

Low norepinephrine activity

Low norepinephrine levels are a sign of several serious medical conditions, including:

Each of these conditions has its own symptom profile. However, they also have several common symptoms, many of which indicate low norepinephrine levels.

This includes:

High norepinephrine activity

A somewhat high NE activity makes you happy, but a really high NE level makes you euphoric. Many recreational drugs cause high levels of norepinephrine and another neurotransmitter, dopamine .

Conditions associated with elevated NE levels include:

  • Anxiety disorders
  • Pheochromocytoma , adrenal tumor
  • Chronic stress
  • Manic phase of bipolar disorder

Similar to conditions associated with low norepinephrine levels, conditions associated with elevated EN levels also have unique and common symptoms.

Overlapping symptoms indicating high norepinephrine levels include:

Paroxysmal sympathetic hyperactivity (PSH) is a term that describes a group of symptoms associated with getting stuck in a fight or flight mode, a possible result of too high levels of norepinephrine.

Traumatic brain injury is one of the most common causes of PSH, but it is also associated with stroke , spinal cord injury , and inflammation in the brain ( encephalitis ).

Symptoms of paroxysmal sympathetic hyperactivity include:


Having too much or too little NE can cause symptoms common to many health conditions. If you experience mood swings, anxiety, headaches, fatigue, or other symptoms associated with EN, your healthcare provider may order a blood or urine test to measure your norepinephrine level.

Watch out

Changes in norepinephrine levels can contribute to or result from the conditions described above. But rather than treating the norepinephrine imbalance itself, healthcare providers treat a related condition and monitor the patient's symptom response.

Depending on your condition, your doctor may prescribe a drug that affects the activity of norepinephrine.

Norepinephrine antagonists

Norepinephrine antagonists are drugs that lower blood pressure and heart rate by suppressing the activity of norepinephrine. They are often used to treat high blood pressure, congestive heart failure , heart rhythm problems, and angina (chest pain that occurs when there is not enough blood flow to the heart).

Norepinephrine antagonists have several effects that are useful in treating other conditions in which norepinephrine levels are also high. Although not FDA approved for this purpose, norepinephrine antagonists can be used off-label for ADHD, insomnia, post-traumatic stress disorder (PTSD), anxiety disorders, and more.

Commonly prescribed norepinephrine antagonists include:

Beta blockers

Beta-blockers block the binding of norepinephrine to receptors in the sympathetic nervous system. By doing so, they relax the heart and lower blood pressure.

Beta-blockers have traditionally been used to treat high blood pressure and angina pectoris. They can also be prescribed off-label to treat anxiety disorders and related symptoms, including migraines and nightmares, or to prevent PTSD after a traumatic event.

Commonly prescribed beta blockers include:

  • Sectral (acebutolol)
  • Levatol (penbutolol)
  • Inderal ( propranolol )

Serotonin-norepinephrine reuptake inhibitors

Serotonin and norepinephrine reuptake inhibitors (SNRIs) are medications used to treat anxiety and depression, but they can also be used to treat panic disorder, ADHD, obsessive compulsive disorder, and more.

SNRIs increase norepinephrine activity by preventing NE reabsorption by nerve cells. These medications are effective in improving mood, energy, and concentration, along with other symptoms associated with low norepinephrine levels.

Commonly assigned SNRIs include:


Amphetamines increase the activity of norepinephrine, stimulating its release and preventing its reabsorption in nerve cells.

These medications are considered first-line ADHD medications because they increase alertness and reduce impulsivity. This makes it easier for people with ADHD to accomplish tasks and achieve goals.

Commonly prescribed amphetamines include:

  • Adderall (dextroamphetamine)
  • Ritalin (methylphenidate)


Norepinephrine antagonists and beta-blockers reduce the activity of norepinephrine and are useful in the treatment of depression, anxiety, and panic disorder. SNRIs and amphetamines increase norepinephrine activity and help improve mood, energy, and concentration.

Natural ways to increase norepinephrine levels

Keep in mind that norepinephrine is part of your body's response to stress. Therefore, one of the best ways to maintain a balanced NE level is to reduce the physical and emotional stress in your life.

People with mild norepinephrine deficiency can improve their symptoms by making healthy lifestyle changes, such as:

  • Exercise regularly
  • Sleep a little
  • Set and achieve goals
  • Enjoy music or art
  • To meditate
  • Eat a healthy and balanced diet.

If you have depression, anxiety, post-traumatic stress disorder, or another disorder that affects your quality of life, these methods may help, but they may not be enough to treat your condition. Talk to your doctor.

Medical use of norepinephrine

A formulation of norepinephrine called levofed is used in the emergency room to raise blood pressure, which drops to dangerously low levels (acute hypotension) due to complications from surgery or illness.

Levofed is often prescribed for cardiac arrest to restore blood flow. It is also commonly used to correct hypotension in people being treated for sepsis , a condition in which the body reacts to infection by damaging its own tissues.

Levofed is injected through a dropper into a vein. Possible side effects of the drug include:

  • Slow and irregular heart rate
  • Decreased urination
  • Difficulty breathing
  • Changes in vision, speech, or balance.
  • Strong headache


Norepinephrine is a hormone and neurotransmitter that affects many aspects of your mental, emotional, and physical health. Low levels of norepinephrine are constantly at work in your brain and body, but levels rise when you face stress, danger, or other threat.

If you experience symptoms that may be related to norepinephrine, your healthcare provider may order tests to measure the amount of NE in your system. If treatment is needed, it will focus on the underlying disease. Prescription medications that balance norepinephrine can help improve your symptoms.

Get the word of drug information

Trauma and chronic stress can lead to imbalances in hormones and neurotransmitters. Ultimately, this can seriously affect your overall health and well-being.

If you suffer from chronic stress or trauma, or just need to talk, tell your doctor. Protecting your mental health is just as important as protecting your physical health.

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