What is Vasoconstriction?

What is Vasoconstriction?

Vasoconstriction represents a condition in which blood vessels constrict and disturb the blood flow. Vaso in vasoconstriction means vessels and constriction is when they show a tightening or shrinking like effect. It is also called vasospasm.

When vasoconstriction occurs it narrows the opening of the blood vessel. It may sound abnormal but vasoconstriction is a normal body mechanism. This is an automated effect that may have multiple reasons.

How vasoconstriction takes place?

The blood vessels are made of smooth muscles. Your body cannot voluntarily control them like skeletal muscles for which you use you move your body. So the blood vessels are self-driven but they may respond to certain signaling channels. For example, certain chemical signals may cause them to constrict or relax.

Some of these chemicals include the following.

  • Epinephrine
  • Angiotensin II
  • Norepinephrine
  • Vasopressin

The walls of arteries are made of muscles that are why they can constrict. However, the walls of thin blood capillaries cannot constrict.

Also read: Common signs that you have a High Blood Pressure

Reasons behind vasoconstriction

There are many conditions that may result in vasoconstriction. Some of them are as follows.

  • Many times it occurs to stabilize the blood pressure. The narrowing of blood vessels makes the blood pressure to rise. So when a person has low blood pressure, vasoconstrictions help to raise it to a suitable level.
  • It helps to retain the body heat even in the extreme cold temperature. It reduces the loss of heat and thus marks itself as a survival aid.
  • It regulates the overall blood circulation in a human body. When other factors reduce or disturb the blood flow making the body to suffer from hypertension or hypotension, this self-administered mechanism regulates it.
  • As it is directly related to the blood flow, it also helps to distribute nutrients and oxygen to every body cell. This way all organs receive sufficient nutrients and oxygen and operate well.
  • Lastly, vasoconstriction also helps to protect the excessive blood loss and fluid loss.

Although it is now clear that vasoconstriction is a normal body process but abnormal vasoconstriction can initiate other health dangers. For example, it may elevate blood pressure to an extremely high level or cause a headache.

Note that this abnormal vasoconstriction is not a normal process. It is usually a side effect of any medicine, food, drug or any allergic reaction. Too much salt or caffeine can also trigger it.

The image is taken from “blog.nus.edu.sg”

How vasoconstriction affects blood pressure?

During the process of constriction, the space inside the blood vessels is reduced. It means blood flow will reduce too. Meanwhile, the resistance of blood to pass through the vessel also increases. Overall this leads to a high blood pressure where the blood flow is strong due to less space inside vessels to pass.

This high blood pressure, if untreated may cause a number of health problems such as headache, circulatory problems, vision-related issues, and heart problems.

Vasodilation is the opposite of vasoconstriction. It happens when the blood vessels are relaxed, causing blood flow to increase. It results in reducing blood pressure.

How certain foods cause vasoconstriction?

Foods and beverages that are high in salt and caffeine can cause vasoconstriction. If you often experience fluctuating blood pressure, it is better to limit the foods high in salt and caffeine.

  • Avoid all packaged and frozen foods
  • Limit eating fast food
  • Avoid using canned and deli meat
  • Follow a moderate use of alcohol

Also read: Caffeine, Espresso And High Blood Pressure: What Is The Connection?

Common medicines that may trigger vasoconstriction

Some medicines act to relieve low blood pressure and are called vasoconstrictors. These medicines also help when a body is in shock or suffering from excessive blood loss or an allergic reaction.

Some prescription medicines trigger vasoconstriction but it is to help a medical problem. For example, a medicine that causes vasoconstriction may help against internal inflammation or blood loss. Some of these medicines, which act vasoconstrictors, are as follows.

  • Alpha-adrenoceptor agonists
  • Vasopressin analogs
  • Phenylephrine
  • Dopamine
  • Dobutamine
  • Serotonin 5-hydroxytryptamine agonists
The image is taken from simple.wikipedia”

Health risks associated with vasoconstriction

The side effects of many medicines or drugs may also cause abnormal vasoconstriction. This way, it surely causes health problems. The severity of these health problems depends upon where is this happening and how long is it taking.


Many times abnormal vasoconstriction may cause a stroke or a similar injury. It happens when a blood vessel ruptures due to pressure in the brain. The blood vessels narrow more to save the blood leading to vasoconstriction. But it also causes to reduce the blood and oxygen supply to the brain and hence the body is under a stroke.

The common signs of having a vasoconstriction-liked stroke are;

  • Headache
  • Dizziness
  • Numbness
  • Loss of balance
  • Weakness
  • Breathing difficulties
  • Walking difficulties
  • Blurry vision
  • Difficulty in speaking

If these symptoms become evident, the person requires immediate medical care. Call an ambulance as soon as these signs show up.

Raynaud’s phenomenon

Raynaud’s phenomenon is a rare condition that affects some parts of the body. It causes a numb feeling due to the disturbed blood supply to that part. The common areas where Raynaud’s phenomenon may hit are; hands, feet, nose, lips, ears, and nipples.

Most of the time it happens because of a drop in temperature. People living in the extreme cold often experience this. Overall it is not a harmful problem but it is discomforting and abnormal. It may also increase the chances to get skin infections more than normal.

Also read: Most Common Reasons To Have Cold Feet and Toes

Reversible cerebral vasoconstriction syndrome

Reversible cerebral vasoconstriction syndrome or RCVS is another weird medical condition vasoconstriction causes. Most of the times it is reversible and the person recovers in a few weeks or months.

In extreme cases, RCVS may end at a stroke. When the blood and nutrients are limited for visceral body organs especially the brain, it causes extreme damage to the body.

There are also chances of babies to experience RCVS. Mostly it shows up as an outcome of some medicines. For example, chemotherapy drugs are much likely to cause it.

The common signs of RCVS include the following

  • Abrupt headache
  • Visionary changes
  • Seizures
  • Difficulty in breathing and speaking
  • Weakness and difficulty in walking

The final word

Vasoconstriction is a natural body process that helps to maintain healthy blood pressure. It also helps the body to retain the heat and live in cold temperatures.

Vasoconstriction only causes a problem when it is abnormal. Abnormal vasoconstriction is a result of medicinal side effects, food and alcohol intake. It is better to talk to a healthcare provider if you have questions on vasoconstriction and how is it affecting your life.

Do not hesitate to fix an appointment if you experience any symptoms of abnormal vasoconstriction. In extreme cases, call an ambulance and consider it as a medical emergency.




The author is a Medical Microbiologist and healthcare writer. She is a post-graduate of Medical Microbiology and Immunology. She covers all content on health and wellness including weight loss, nutrition, and general health. Twitter @Areeba94789300

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