Vasoconstriction

What Is Vasoconstriction?

Vasoconstriction is what healthcare providers call it when the muscles around your blood vessels contract to make the space inside smaller. This is the opposite of vasodilation, which opens your blood vessels to make the space inside bigger.

Your vasomotor nerves (part of your sympathetic nervous system) can tell your muscles to adjust the amount of space inside your blood vessels. This can happen in response to stress, trauma or other causes. Certain hormones trigger vasoconstriction:

• Angiotensin
• Vasopressin
• Epinephrine
• Norepinephrine

When blood vessels become narrow, it takes more pressure for blood to travel through them. This is how vasoconstriction increases blood pressure.

Are there benefits?

Vasoconstriction can help or hurt your body, depending on the situation. When you’re outside in the cold, peripheral vasoconstriction helps your body keep from losing too much heat and getting hypothermia (low body temperature). Your body does this by making less blood flow to your skin.

Sometimes, healthcare providers use medicines to create vasoconstriction. These vasoconstrictors can help you if you have a medical condition like shock.

What Causes Vasoconstriction?

What are the most common causes?

Many different things can cause vasoconstriction. The most common causes include:

• Prescription or nonprescription medicines: Decongestants and other medicines have ingredients that cause blood vessels to narrow to provide relief.
• Certain medical conditions: For example, Raynaud’s syndrome tightens blood vessels in your hands and feet.
• Stress and other mental health problems: Your body releases substances that cause your blood vessels to tighten as if you were in danger.
• Blood vessel injury: Vasoconstriction stops the blood flow as a first step in making a repair.
• Tobacco products: Chemicals in cigarettes make blood vessels tighten.
• Cold environment: Your body stays warmer when less blood is flowing to your skin.
• Infection: Peripheral vasoconstriction helps raise your body temperature in response, and you get a fever.
• Trauma: Constricting blood vessels helps limit blood loss after an injury.

What are the risks of vasoconstriction?

Too much vasoconstriction can cause problems, like:

• Causing too little blood to reach your fingers or toes, as in acrocyanosis or Raynaud’s syndrome
• Raising the risk of heat stroke in someone with hyperthermia
• Putting people with coronary artery disease at a higher risk of a heart problem flaring up when they’re under stress
• Increasing blood pressure (hypertension)
• Causing high blood pressure in your lung arteries (pulmonary hypertension)
• Causing severe headaches (reversible cerebral vasoconstriction syndrome)

What are the signs of excessive vasoconstriction?

Blood vessels with too much constriction can lead to a lack of blood flow. The tissues they supply can’t get enough oxygen. Depending on which body part this affects, you can have:

• Pain in your chest, belly or limbs
• Shortness of breath
• Loss of color or warmth in an arm or leg
• Dizziness

Care and Treatment

How do I reverse vasoconstriction?

For some medical problems, like Raynaud’s phenomenon, you’ll need medication to widen your blood vessels.

Actions you can take include:

• Warm up your body to widen your blood vessels.
• Bring down your stress level.
• Avoid eating too much salt.
• Get some physical activity.
• Stop smoking.

You can’t prevent all vasoconstriction of blood vessels. And you wouldn’t want to when you’re cold.

When should I contact a healthcare provider?

You should seek medical help when you have a bothersome or serious problem, like:

• Hyperthermia
• Pulmonary hypertension
• High blood pressure