Raynaud's disease

• Cold fingers and toes
• Sequence of color changes in your skin in response to cold or stress
• Numb, prickly feeling or stinging pain upon warming or relief of stress

During an attack of Raynaud's, affected areas of your skin usually turn white at first. Then, the affected areas often turn blue, feel cold and numb, and your sensory perception is dulled. As circulation improves, the affected areas may turn red, throb, tingle or swell. The order of the changes of color isn't the same for all people, and not everyone experiences all three colors.

Occasionally, an attack affects just one or two fingers or toes. Attacks don't necessarily always affect the same digits. Although Raynaud's most commonly affects your fingers and toes, the condition can also affect other areas of your body, such as your nose, lips, ears and even nipples. An attack may last less than a minute to several hours.

People who have Raynaud's accompanied by another disease will likely also have signs and symptoms related to their basic underlying condition.

Causes

Doctors don't completely understand the cause of Raynaud's attacks, but blood vessels in the hands and feet appear to overreact to cold temperatures or stress:

• Cold temperatures. When your body is exposed to cold temperatures, your extremities lose heat. Your body slows down blood supply to your fingers and toes to preserve your body's core temperature. Your body specifically reduces blood flow by narrowing the small arteries under the skin of your extremities. In people with Raynaud's, this normal response is exaggerated.
• Stress. Stress causes a similar reaction to cold in the body, and likewise the body's response may be exaggerated in people with Raynaud's.

Blood vessels in spasm

With Raynaud's, arteries to your fingers and toes go into what's called vasospasm. This narrows your vessels dramatically and temporarily limits blood supply. Over time, these same small arteries may also thicken slightly, further limiting blood flow. The result is that affected skin turns a pale and dusky color due to the lack of blood flow to the area. Once the spasms go away and blood returns to the area, the tissue may turn red before returning to a normal color.

Cold temperatures are most likely to trigger an attack. Exposure to cold can be as simple as putting your hands under a faucet of running cold water, taking something out of the freezer or exposure to cold air. For some people, exposure to cold temperatures isn't necessary. Emotional stress alone can cause an episode of Raynaud's.

Raynaud's may be partly an inherited disorder.

Primary vs. secondary Raynaud's

Raynaud's occurs in two main types:

• Primary Raynaud's. This is Raynaud's without an underlying disease or associated medical problem that could provoke vasospasm. Also called Raynaud's disease, it's the most common form of the disorder.
• Secondary Raynaud's. Also called Raynaud's phenomenon, this form is caused by an underlying problem. Although secondary Raynaud's is less common than the primary form, it tends to be a more serious disorder. Signs and symptoms of secondary Raynaud's usually first appear at later ages — around 40 — than they do for people with the primary form of Raynaud's.

Causes of secondary Raynaud's include:

• Scleroderma. Raynaud's phenomenon occurs in the majority of people who have scleroderma — a rare disease that leads to hardening and scarring of the skin. Scleroderma, a type of connective tissue disease, results in Raynaud's because the disease reduces blood flow to the extremities.
• Lupus. Raynaud's is also a common problem for people with lupus erythematosus — an autoimmune disease that can affect many parts of your body, including your skin, joints, organs and blood vessels. An autoimmune disease is one in which your immune system attacks healthy tissue.
• Rheumatoid arthritis. Raynaud's may be an initial sign of rheumatoid arthritis — an inflammatory condition causing pain and stiffness in the joints, often including the hands and feet.
• Sjogren's syndrome. Raynaud's phenomenon can also occur in people who have Sjogren's syndrome — an autoimmune disorder that may accompany scleroderma, lupus or rheumatoid arthritis.
• Diseases of the arteries. Raynaud's phenomenon can be associated with various diseases that affect arteries, such as atherosclerosis, which is the gradual buildup of plaques in blood vessels that feed the heart (coronary arteries), or Buerger's disease, a disorder in which the blood vessels of the hands and feet become inflamed. Primary pulmonary hypertension, a type of high blood pressure that affects the arteries of the lungs, can be associated with Raynaud's.
• Carpal tunnel syndrome. The carpal tunnel is a narrow passageway in your wrist that protects a major nerve to your hand. Carpal tunnel syndrome is a condition in which pressure is put on this nerve, producing numbness and pain in the affected hand. The affected hand may become more susceptible to cold temperatures and episodes of Raynaud's.
• Repetitive trauma. Raynaud's can also be caused by repetitive trauma that damages nerves serving blood vessels in the hands and feet. Some people who type or play the piano vigorously or for long periods of time may be susceptible to Raynaud's. Workers who operate vibrating tools can develop a type of Raynaud's phenomenon called vibration-induced white finger.
• Smoking. Smoking constricts blood vessels and is a potential cause of Raynaud's.
• Injuries. Prior injuries to the hands or feet, such as wrist fracture, surgery or frostbite, can lead to Raynaud's phenomenon.
• Certain medications. Some drugs — including beta blockers, which are used to treat high blood pressure; migraine medications that contain ergotamine; medications containing estrogen; certain chemotherapy agents; and drugs that cause blood vessels to narrow, such as some over-the-counter cold medications — have been linked to Raynaud's.
• Chemical exposure. People exposed to vinyl chloride, such as those who work in the plastics industry, may develop an illness similar to scleroderma. Raynaud's can be a part of that illness.
• Other causes. Raynaud's has also been linked to thyroid gland disorders. 

Risk factors

Risk factors for primary Raynaud's include:

• Your gender. Primary Raynaud's affects women more than men.
• Your age. Although anyone can develop the condition, primary Raynaud's often begins between the ages of 15 and 30.
• Where you live. The disorder is also more common in people who live in colder climates.
• Your family history. Additionally, a family history appears to increase your risk of primary Raynaud's. About one-third of people with primary Raynaud's have a first-degree relative — a parent, sibling or child — with the disorder.

Risk factors for secondary Raynaud's include:

• Associated diseases. These include conditions such as scleroderma and lupus.
• Certain occupations. People in occupations that cause repetitive trauma, such as workers who operate tools that vibrate, also may be more vulnerable to secondary Raynaud's.
• Exposure to certain substances. Smoking, medications that affect the blood vessels and exposure to chemicals such as vinyl chloride are associated with an increased risk of Raynaud's.

Complications

If Raynaud's is severe — which is rare — blood circulation to your fingers or toes could permanently diminish, causing deformities of your fingers or toes.

If an artery to an affected area becomes blocked completely, sores (skin ulcers) or dead tissue (gangrene) may develop. Ulcers and gangrene can be difficult to treat.

References

http://www.mayoclinic.org/diseases-conditions/raynauds-disease/basics/definition/con-20022916

https://www.hse.ie/eng/health/az/R/Raynaud's-phenomenon/Causes-of-Raynaud's.html

http://www.medicinenet.com/raynauds_phenomenon/article.htm

http://emedicine.medscape.com/article/331197-overview

Diagnosis

To diagnose Raynaud's, your doctor will ask detailed questions about your symptoms and medical history and conduct a physical examination. Your doctor may also run tests to rule out other medical problems that may cause similar signs and symptoms, such as a pinched nerve.

Your doctor may perform a simple test called a cold-stimulation test during your office visit. This test may involve placing your hands in cool water or exposing you to cold air, to trigger an episode of Raynaud's.

Sorting out primary vs. secondary Raynaud's

To distinguish between primary and secondary Raynaud's, your doctor may perform an in-office test called nail fold capillaroscopy. During the test, the doctor examines your nail fold — the skin at the base of your fingernail — under a microscope. Tiny blood vessels (capillaries) near the nail fold that are enlarged or deformed may indicate an underlying disease. However, some secondary diseases can't be detected by this test.

If your doctor suspects that another condition, such as an autoimmune or connective tissue disease, underlies Raynaud's, he or she may order blood tests, such as:

• Antinuclear antibodies test. A positive test for the presence of these antibodies — produced by your immune system — indicates a stimulated immune system and is common in people who have connective tissue diseases or other autoimmune disorders.
• Erythrocyte sedimentation rate. This blood test determines the rate at which red blood cells settle to the bottom of a tube in the space of an hour. A faster than normal rate may signal an underlying inflammatory or autoimmune disease. Autoimmune diseases are commonly associated with secondary Raynaud's.

There's no single blood test to diagnose Raynaud's. Your doctor may order other tests, such as those that rule out diseases of the arteries, to help pinpoint a disease or condition that may be associated with Raynaud's.