Blood vessels circulate blood throughout your body. They help deliver oxygen to vital organs and tissues, and also remove waste products. Blood vessels include veins, arteries and capillaries.
Blood vessels are channels that carry blood throughout your body. They form a closed loop, like a circuit, that begins and ends at your heart. Together, the heart vessels and blood vessels form your circulatory system. Your body contains about 60,000 miles of blood vessels.
There are three types of blood vessels:
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The function of blood vessels is to deliver blood to the organs and tissues in your body. The blood supplies them with the oxygen and nutrients they need to function. Blood vessels also carry waste products and carbon dioxide away from your organs and tissues.
Each type of blood vessel serves a different function:
There are blood vessels throughout your body. The main artery is your aorta, which connects to the left side of your heart. It runs down through your chest, diaphragm and abdomen, branching off in many areas. Near your pelvis, your aorta branches into two arteries that supply blood to your lower body and legs.
The main vein in your body is the vena cava. The superior vena cava is in the upper right part of your chest. It carries blood from your head, neck, arms and chest back to your heart. The inferior vena cava is near the right side of your diaphragm. It brings blood from your legs, feet, abdomen and pelvis back to your heart.
Blood vessels have a tube-like shape, but they rarely run in a straight line. Some are big enough to see under your skin. If you’ve ever had your blood drawn, you may have noticed veins on the inside of your arm. They might appear blue under your skin, even though your blood is red.
Some, like the aorta, have a wide diameter. For example, a normal aorta in the abdomen is about 2 centimeters wide (about the size of a nickel). But other blood vessels, such as capillaries, are extremely small. They range from 2 to 12 micrometers, which is even less than the diameter of a human hair.
Blood vessels have three layers of tissue:
A wide range of problems can affect your blood vessels, including:
Some blood vessel disorders are very common. For example, nearly half of all adults in the U.S. have high blood pressure. But others, such as vascular malformations, are rare. Less than 1% of the population develops this condition.
Your risk for vascular disease increases if you:
Symptoms vary widely across the different types of blood vessel disorders. Some, such as aneurysms or vascular malformations, may not cause symptoms until a serious problem develops.
In general, it’s a good idea to talk to your doctor if you experience:
Your healthcare provider may use a variety of tests to diagnose problems in your blood vessels, including:
Treatment for blood vessel disorders may include:
There are a variety of ways you can improve the health of your blood vessels, including:
Seek immediate medical attention if you experience:
A note from Cleveland Clinic
Blood vessels carry blood from your heart to the rest of your body. They’re essential for making sure your organs and tissues get the oxygen and nutrients they need to work. But blood vessels can develop problems, such as blockages or enlargement. Severe blood vessel disorders can be life-threatening. You can keep your blood vessels in good shape by maintaining a healthy lifestyle.
Last reviewed by a Cleveland Clinic medical professional on 07/09/2021.
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