Veins appear blue because blue light is reflected back to our eyes. ... Blue light does not penetrate human tissue as deeply as red light does. As a result, veins that are close to the surface of the skin will be more likely to reflect blue light back to the eye.”
It is a common myth that veins are blue because they carry deoxygenated blood. Blood in the human body is red regardless of how oxygen-rich it is, but the shade of red may vary. The level or amount of oxygen in the blood determines the hue of red.
The veins themselves are not blue, but are mostly colorless. It is the blood in the veins that gives them color. Furthermore, the blood in human veins is also not blue. Blood is always red.
Maybe you've heard that blood is blue in our veins because when headed back to the lungs, it lacks oxygen. But this is wrong; human blood is never blue. The bluish color of veins is only an optical illusion. Blue light does not penetrate as far into tissue as red light.
Dark-colored or blue veins are normal and healthy, although it can be a bit strange seeing sudden prominent blue veins pop up on your skin. Veins can become more visible due to various reasons, including decreased body fat, aging, genetics, physical activity, pregnancy, sun exposure, and certain medical conditions.
The primary reason veins are blue is the way wavelengths of light hit the skin. White light can carry colors and waves with varying lengths. Red has the ability to travel the farthest. Violet waves are the shortest, and all the other colors fall somewhere in between.
It's red because of the red blood cells (hemoglobin). Blood does change color somewhat as oxygen is absorbed and replenished. But it doesn't change from red to blue. It changes from red to dark red.
Bulging veins can occur due to: Temporarily rising blood pressure and/or body temperature. When you're exercising or working with your hands, blood flow in the area increases. Veins also swell in warmer conditions, as the body sends blood toward the surface of the skin to cool down.
The colors of arterial and venous blood are different. Oxygenated (arterial) blood is bright red, while dexoygenated (venous) blood is dark reddish-purple.
If you have pale skin it's not uncommon to see blue veins traveling across your arms, neck, chest and legs. In fact, visible veins that show through the skin's surface are just a part of life. But if you have big, blue, bulging veins you have varicose veins—and a red flag for vein health.
The good news is that visible veins are not always cause for concern. They can be indicators of regular exercise, sun exposure, or even hot weather. We always recommend visiting a vein specialist to evaluate any visible veins of concern.
Since arteries carry oxygen-rich blood away from the heart and veins carry oxygen-depleted blood back to the heart, some people believe that veins appear blue because blood without oxygen is blue. But it's not true! Blood is always red. Oxygen-rich blood is bright red as it leaves the heart.
Flip Your Wrist For More Info
Blue or purple wrist veins typically indicate that you have cool undertones, while green or olive equates to warm, and blue-green veins suggest that neutral undertones are in effect. Cool = Veins on the underside of your wrist appear blue/purple.
In many cases, vein popping out is normal to see in certain situations. Bulging leg veins don't often indicate an underlying health problem or confirm a critical medical issue. If you notice bulging leg veins in your legs, don't immediately panic.
This bulging is neither good nor bad but simply a result of normal physiological mechanisms that result from the rise in arterial blood pressure during exertion.
During intense exercise, your body will naturally work harder to pump blood. As a result, you may experience temporary bulging of the veins during intense exercise. This is a perfectly normal response and does not indicate that there is anything wrong with your body.
Darkened blood color is often observed in critically ill patients generally because of decreased oxygen saturation, but little is known about the other factors responsible for the color intensity. In addition, quantitative blood color examination has not been performed yet.
One of the world's rarest blood types is Rh- null. It is called the "golden blood". This blood type is distinct from Rh-negative since it has none of the Rh antigens at all. There are less than 50 people in the world population who have this blood type.
High levels of oxygen reflect red, and high levels of carbon dioxide reflect blue, which, when mixed with the yellowish colour of fat and or the skin, end up looking green.
In most cases, there is no need to worry if your veins appear green because it usually indicates that blood vessels are working well. Green veins on the hand or legs are superficial veins that lie close to the surface of your skin.
Blood leaks into tissues under the skin and causes the black-and-blue colour. As bruises (contusions) heal, they often turn colours, including purplish black, reddish blue, or yellowish green.