The sign of any blue color of the skin is always a cause for concern. Most of us know that a blue tinge can be a sign of low oxygen levels and is usually linked to serious and even life-threatening conditions. Without prompt medical treatment it can be fatal, sometimes within minutes. However, this is not always the case. There are times when a blue tinge may not be due to a serious medical condition and could even be entirely harmless.
How does skin turn blue?
It is important to first understand the reason for the natural brown color of skin. The pigment melanin is produced by specialized cells known as melanocytes. This brown pigment is the main contributor to skin color and varies in quantity on different parts of the body. It is determined by both genetic and environmental factors. However, melanin is not the only contributor to skin color.
The tiny blood vessels under the skin surface also contribute to skin color. When these vessels widen and more blood flows through it the skin takes on a pinker to redder hue. The red color of blood is due to oxygen that binds to the iron in hemoglobin of red blood cells. In a low carbon dioxide state, the skin may appear blue due to alterations in the blood’s ability to absorb or reflect light. However, the blood is not actually blue.
This bluish tinge with low blood oxygen levels is known as cyanosis. When it affects the extremities only, like the hands and feet, then it is referred to as peripheral cyanosis. It is usually due to less severe causes than central cyanosis, which may be evident on the face or lips as well. Sometimes the bluish tinge has nothing to do with the blood and is entirely due to surface factors.
Causes of Blue Hands and Fingers
Making contact with blue colored substances are another possible cause. It may be obvious substances like blue paint or blue dyes while at other times the substance that causes bluish discoloration of the skin may not even appear blue until it reacts with the skin surface.
Cold is another factor that can cause a bluish discoloration as a result of severely constricting blood vessels as a way to preserve heat. Immersing the hands in ice water or leaving the hands unprotected in very cold weather can result in a bluish color.
High altitude is another environmental factor that may lead to low blood oxygen levels due low oxygen levels in the environment.
Circulatory causes include disorders of the blood vessels and heart. If blood is not properly circulated, it may not reach every part of the body in sufficient quantity, blood may pool at one area for long periods or it is not properly perfused at the lungs. Conditions where circulation is compromised includes:
- Raynaud’s phenomenon is a condition where the arteries in the hand and fingers constrict suddenly (spasm) usually in response to cold and stress. This is usually temporary.
- Peripheral arterial disease (PAD) is where the arteries become narrowed leading to a reduction in blood supply to the target area. The narrowing is usually due to the build up of fatty plaques in the artery wall (atherosclerosis).
- Blood clots may form in the blood vessel (thrombus) or form elsewhere and lodge in a distant blood vessel (embolus) resulting in a partial or complete blockage of the vessel.
- Cyanotic heart disease is a group of heart conditions where the flow of blood to the lungs is affected. It is seen with congenital heart diseases (present from birth) resulting in low blood oxygen levels.
- Blood disorders where the oxygen-carrying capacity of blood is expected mainly due to abnormalities with hemoglobin or red blood cell formation.
The airways and lungs play an obvious and integral role as a possible cause of bluish discoloration. If the entry of air into the lungs is impeded or its absorption into the bloodstream, there will be low blood oxygen levels.
- Chronic obstructive pulmonary disease (COPD) is a group of long term airway or lung diseases, such as chronic bronchitis and emphysema, which is often associated with tobacco smoking.
- Asthma occurs with spasm of the bronchi and mucus production within the airways that reduces air flow through it. It is often associated with an allergic disposition.
- Infections can also affect the passage of air and gas absorption into the bloodstream. It usually occurs with severe infections like croup (upper airways) or the lungs (pneumonia).
- Pneumoconiosis are lung diseases associated with inhalation of dusts often due to occupational factors. Allergic pneumonitis is inflammation of the lung due to allergy-related factors.
A number of substances, including illicit drugs, pharmaceuticals and even some poisons, can lead to low blood oxygen levels. With drugs and medication, the breathing rate may be drastically reduced thereby reducing oxygenation of the blood. This effect can be compounded with the use of alcohol or other central nervous system depressants.
With poisons there may be a dual effect of reduced breathing rate or dept as with drugs, as well as oxygen being blocked from binding with the red blood cells. These types of poisons may include arsenic and cyanide. Certain substances, including some venoms, can also cause rapid destruction of red blood cells thereby reducing the oxygen-carrying capacity of the blood.
The bluish discoloration of the hands and fingers is a symptom and not a disease on its own. It is usually referred to as cyanosis but this term only applies if it is due to low blood oxygen levels. Other signs and symptoms that may also accompany the bluish discoloration includes:
- Tingling and numbness of the hands and fingers.
- Discomfort, burning sensation or pain.
- Cramps of the muscles in the hands and fingers.
- Coldness of the hands and fingers.
Cyanosis should always be considered as a serious symptom and urgent medical attention needs to be sought. The presence of blue lips, cold and clammy skin, confusion and sudden changes in heart rate and blood pressure is considered as as medical emergency.