Why Are My Veins Blue?

Font Size:
thigh with blue veins

Connect With Vein Specialists Near You

Where do you need a vein specialist?

Topics Covered in this Blog:

  1. Your Body’s Circulatory System
  2. Blue Veins vs. Green Veins
  3. Why Are My Veins Blue?
  4. Why Are My Veins Green?
  5. Should I Worry About Sudden Prominent Blue Veins?
  6. Vein Disease and Treatment
  7. Schedule a Consultation

If blood is red, why do veins appear blue or green?

There isn’t a single answer. In fact, there are many reasons why blue or green veins are visible through skin. Some of these include the varying wavelengths of different colors (observable light to the human eye), your natural complexion, your age, and even your body mass index (BMI).

One common and potentially dangerous health condition that may be behind your visible veins is vein disease, or venous insufficiency. Vein disease is the underlying cause of varicose veins, spider veins, and other venous issues.

Vein disease symptoms can include:

  • Swelling in your legs and ankles
  • Cramps or achiness in the thigh or calf
  • Tired or heavy legs
  • Restlessness, especially at night
  • Itchy, dry, or hardened skin on your legs
  • Wounds on your legs or ankles that take a long time to heal or don’t heal at all
  • Leg pain that goes away when you walk or elevate your legs

Symptoms Quiz 5 Quick Questions to Evaluate Your Vein Health

When left untreated, vein disease can place you at increased risk for several dangerous health conditions. These include blood clots, pulmonary embolism, and venous ulcers (open, non-healing wounds). It is important to know that sudden prominent blue veins that appear on your legs can be a sign of trouble.

Below, we provide answers to some common questions including: Why are my veins so blue? and why are my veins green? We also discuss your overall circulatory system, when to see a doctor, and how to find minimally invasive, office-based vein treatment. If you have additional questions, we recommend consulting a vein specialist.

Your Body’s Circulatory System

Your circulatory system is responsible for transporting blood around the body. You are probably already aware that your heart pumps blood, oxygen, and nutrients throughout. Arteries, capillaries, and veins are the blood vessels involved in this process.

Your arteries carry bright red, oxygen-rich blood from your heart to other regions of your body, including organs and tissue. Your capillaries’ job is to connect the arteries to your veins. Finally, your veins are responsible for delivering dark red, oxygen-depleted blood back to the heart for re-oxygenation.

While arteries are found deep in the body, veins are generally close to the skin. Their location makes them more visible than other types of blood vessels. Some individuals, such as those with light complexions or aging skin, naturally have more visible veins. Others find that certain lifestyle factors can influence their veins’ appearance. For instance, those with a low body mass index (BMI) due to weightlifting or other factors tend to have more visible blue veins.

facts about blood flow within your veins

Blue Veins vs. Green Veins

Blood pumping away from your heart is bright red, and blood pumping back to your heart is dark red. So, you’re thinking why are my veins green or why are my veins blue?

This visual phenomenon is due to how our eyes perceive the different wavelengths of light. Red light has the longest wavelength, violet light has the shortest, and other colors’ wavelengths are in between. White light contains all colors and wavelengths.

When white light hits the skin, red light can travel further below the surface than blue light. Its longer wavelength reaches deeper where your veins are located. From there, hemoglobin (the protein that makes your blood red) absorbs the red light.

Blue or green light, on the other hand, doesn’t travel as deeply. They are more easily deflected from your skin than red light. So when white light hits your skin, blue and green light isn’t absorbed in the same way as red light. The result is that, despite blood always being red, you ultimately see blue or green veins.

You may also be wondering about blue veins vs. green veins. The exact hue that your veins appear depends on several factors. These include your skin tone, BMI, age, and how deep the veins are located.

Why Are My Veins So Visible?

Why Are My Veins Blue?

There are many potential explanations for the appearance of blue veins, including their location, the different wavelengths of light, your skin tone, age, and BMI. Additionally, venous issues such as vein disease or blood clots can lead to visible blue veins. For a full evaluation of your individual situation, we recommend visiting a vein specialist.

Why Are My Veins Green?

Similar to our answer on why are my veins blue, your veins may appear green due to the different wavelengths of light, the color of your skin, your body weight, your age, and even underlying health conditions like vein disease. If you experience venous symptoms or sudden prominent blue veins or green veins, seek personalized recommendations from a vein specialist.

why do veins often appear blue or green beneath the skin's surface

Should I Worry About Sudden Prominent Blue Veins?

Just because you have visible blue veins on your legs does not mean you need to race to the emergency room. However, there are specific symptoms that you should be on the lookout for. If you experience pain and discomfort due to leg swelling, cramping, heaviness, or itching and burning, it is probably a good idea to get checked out as soon as possible. If your blue veins are symptomatic and raised above the skin, they are probably varicose veins.

Varicose veins are not only a cosmetic issue. They are also a sign that your body’s circulatory system is not working properly. When vein valves malfunction, they can no longer effectively pump blood back to the heart. This results in blood pooling, most often in the legs, ankles, and feet.

Varicose veins can also put you at risk for potentially dangerous health conditions. If you notice sudden prominent blue veins accompanied by skin discoloration or non-healing leg wounds, we recommend seeking medical evaluation immediately. The sudden appearance of visible blue veins accompanied by pain, swelling, tenderness, discoloration, and warmth can indicate deep vein thrombosis (DVT).

DVT is a serious health issue that requires immediate treatment, in part because it can lead to pulmonary embolism, a life-threatening condition. Pulmonary embolism occurs when a piece of DVT breaks off and travels through the bloodstream to the lungs. Another type of blood clot, called superficial thrombophlebitis (ST), may also require urgent medical attention.

Another serious issue to look for is the development of venous ulcers, or open, non-healing wounds on the leg. Venous ulcers require treatment since they can put you at risk for skin and blood infections. Treatment involves addressing the underlying cause –– vein disease.

Bottom line: Visible blue veins on legs can be a sign of vein disease and should be evaluated as soon as possible by an experienced vein specialist. Sudden prominent blue veins accompanied by DVT symptoms are a medical emergency.

Vein Disease and Treatment

Problematic veins are not always visible. You may experience painful vein symptoms like swelling or cramping with no sign of visible blue veins or green veins. Or, your malfunctioning veins may be visible, but not protrude or appear enlarged.

In general, you may be at higher risk for vein disease if you are:

  • Female
  • Over age 50
  • Pregnant
  • Hypertensive
  • Diabetic
  • Closely related to someone with varicose veins
  • Regularly standing or sitting for prolonged periods of time

If you have any concerns about your vein health, it is important to consult a vein specialist. You may benefit from minimally invasive, office-based vein treatments such as:

At USA Vein Clinics, we offer initial consultations during which we can discuss personalized vein treatment recommendations.

Make your appointment here

Schedule a Consultation at USA Vein Clinics

We hope you now have a better answer to the question, “why are my veins blue?” If vein disease is behind your visible veins, our vein specialists can help. Our experts perform a range of minimally-invasive, office-based treatments for varicose veins, spider veins, restless leg syndrome, and other venous conditions. Most of our treatments take less than an hour, from start to finish.

In other words, once you’ve talked to a vein specialist, there’s no need to worry about blue veins vs green veins anymore. Head to one of our state-of-the-art, nationwide clinics in over 100 easy-to-find locations. To learn more about improving your vein health, just schedule an appointment online or call us.

CALL US 888.768.3476

Medically Reviewed By:

Dr. Yan Katsnelson is a philanthropist, business owner, and highly skilled cardiac surgeon. He is the Founder and CEO of USA Vein Clinics, which is part of USA Clinics Group, the parent company of USA Fibroid Centers, USA Vascular Centers, and USA Oncology Centers with more than 100 facilities nationwide. Dr. Yan has established himself as a strong advocate for accessibility and affordability of the most advanced medical care close to home. His mission is to create a positive experience for each patient with compassionate, personalized, and expert care.

Schedule Online
Find a Location