The short answer is, mostly. Vasodilation, or the widening of blood vessels, happens naturally in your body when an increase in blood flow to tissues in your body is needed. It’s a normal process but it can also be part of health issues.

First we’ll look at triggers of vasodilation that you might recognize.

There are many possible causes of vasodilation. Some of them include:

Alcohol

One of the immediate effects of alcohol is vasodilation. This is one of the reasons you may feel warm, sweat, or have flushed skin if you’ve been drinking.

Exercise

As you exercise, your muscle cells consume more and more energy, leading to a decrease in nutrients and an increase in molecules such as carbon dioxide.

This can lead to vasodilation, as the muscles you’re exercising require more nutrients and oxygen.

Inflammation

Inflammation can occur due to a variety of injuries, diseases, or conditions. Vasodilation happens during the inflammatory process in order to allow increased blood flow to the affected area.

This is what causes the heat and redness associated with inflammation.

Temperature

You have receptors in your body called thermoreceptors, which detect changes in the temperature of your environment.

When your thermoreceptors pick up on a higher amount of warmth in your environment relative to cold, vasodilation will occur.

This directs a higher flow of blood toward your skin in an effort to dissipate any excess warmth you’re feeling.

Vasodilator substances produced by the body

There are many substances that your body produces that can lead to vasodilation.

Some examples include things such as nitric oxide and carbon dioxide as well as hormones such as acetylcholine, prostaglandins, and histamine.

Vasodilator medications

Drugs called vasodilators can cause your blood vessels to widen.

They can either act directly on the smooth muscle of the blood vessels or on your autonomic nervous system, which is the part of your nervous system that regulates vasodilation and vasoconstriction.

Vasodilation is the widening of your blood vessels. It happens when smooth muscles found in the walls of arteries or large veins relax, allowing the blood vessels to become more open.

This leads to an increase in blood flow through your blood vessels as well as a decrease in blood pressure.

There are a variety of conditions that can lead to vasodilation. Below, we’ll explore some examples and discuss why vasodilation is an important factor.

Conditions or diseases that cause inflammation

Vasodilation is an important aspect of inflammation. It increases blood flow to the area and also increases the permeability, or leakiness, of the blood vessel walls. Both of these factors help immune cells to more effectively reach the affected area.

Inflammation is a process that’s meant to help rid our bodies of foreign invaders, but in some cases it can be harmful, such as in severe allergic reactions and chronic inflammatory diseases.

Vasodilation related to inflammation can be observed in the following scenarios:

  • Injuries, such as getting a splinter or scrape or twisting an ankle
  • Infections, such as when your nose becomes red and stuffs up during a cold or when an infected wound becomes red and hot to the touch
  • Allergic reactions, which occur when your immune system reacts to a harmless foreign substance. Histamine plays a large role in promoting vasodilation in this case.
  • Chronic diseases or conditions, particularly those in which the immune system attacks healthy cells of the body. Some examples include rheumatoid arthritis, lupus, and inflammatory bowel disease (IBS). People with these conditions may exhibit issues with blood vessel function, including dysfunction of vasodilation. This can lead to cardiovascular problems.

Erythromelalgia

Erythromelalgia is a rare condition that can affect your hands and feet. Symptoms can include severe burning pain, warmth, and redness in the affected area.

In most people with the condition, symptoms aren’t constant but instead occur intermittently.

While what causes erythromelalgia is unknown, some evidence suggests that symptoms may be due to abnormalities in vasodilation and vasoconstriction.

The process of vasodilation naturally leads to a drop in blood pressure. This is due to the widening of the blood vessels, which leads to a greater blood flow and therefore less pressure on the walls of the blood vessels.

Blood pressure that’s abnormally low is referred to as hypotension. Hypotension may cause no problems for some people, but for others it can lead to symptoms such as dizziness, fainting, and nausea. Extreme levels of hypotension can be life threatening.

A number of conditions can cause hypotension, including severe allergic reactions (anaphylaxis), blood loss, dehydration, and severe infection. Certain medications, particularly those used to treat high blood pressure can also lead to hypotension.

A variety of environmental and personal factors can also have an impact on vasodilation, including:

Temperature

Vasodilation occurs when you’re exposed to warmer temperatures. It helps to direct a higher flow of blood toward your skin in order to keep your core body temperature at a normal level.

Prolonged exposure to high temperatures can affect your body’s ability to regulate its temperature, leading to conditions such as heat exhaustion and heat stroke.

Elevation

As you move to higher elevations, there’s less oxygen available in the air that you breathe.

Your body initially responds to this lack of oxygen through vasodilation, allowing more blood flow to your tissues. However, this is then followed by vasoconstriction.

The accompanying vasoconstriction can lead to an increase in blood pressure as well as buildup of fluid in tissues such as the lungs. This condition is called high-altitude pulmonary edema and can be life-threatening. The condition may be treated with vasodilator drugs or supplemental oxygen.

Age

Increasing age is associated with a decrease in function of blood vessels, including vasodilation. This can contribute to the risk of cardiovascular events such as heart disease and stroke.

Weight

People that are obese have been observed to have dysfunction in vasodilation.

In an obese individual, blood vessels are more resistant to vasodilation, which can lead to cardiovascular issues. Weight loss can help to alleviate the dysfunction in vasodilation.

Vasodilator drugs are medications that can cause vasodilation. Many can act directly on the smooth muscle found in the walls of blood vessels. Others can act on the part of the nervous system that regulates vasodilation and vasoconstriction.

Because vasodilation lowers blood pressure, doctors often prescribe vasodilators for conditions such as high blood pressure or heart failure. Some vasodilators are strong medications and can cause side effects such as fast heartbeat, fluid retention, and flushing.

Viagra is an example of a drug that effects vasodilation and isn’t primarily used for high blood pressure treatment. It helps treat erectile dysfunction by affecting the biological pathways that lead to vasodilation of the smooth muscle.

This leads to an increase in blood flow to the penis. A secondary use for Viagra is treating some forms of high blood pressure.

Vasoconstriction is the opposite of vasodilation. While vasodilation is the widening of your blood vessels, vasoconstriction is the narrowing of blood vessels. It’s due to a contraction of muscles in the blood vessels.

When vasoconstriction occurs, the blood flow to some of your body’s tissues becomes restricted. Your blood pressure also rises.

Vasodilation occurs naturally in your body in response to triggers such as low oxygen levels, a decrease in available nutrients, and increases in temperature.

It causes the widening of your blood vessels, which in turn increases blood flow and lowers blood pressure.

Although vasodilation is a natural process, there are situations in which it can be harmful, such as in severe hypotension, allergic reactions, and strong inflammatory responses.

Additionally, factors such as age and weight can also negatively affect vasodilation.

Nonetheless, inducing vasodilation can be a valuable tool to treat conditions such as high blood pressure and even sickness related to high altitude.