What is Raynaud’s?
Pronounced ‘ray-NOHZ’, Raynaud’s syndrome is also known as Raynaud’s phenomenon or Raynaud’s disease. The condition is characterised by restricted (or interrupted) blood flow to the fingers (hands), toes (feet), nose and ears which results in brief episodes of constriction (narrowing), known as vasospasm. Constriction occurs as a result of abnormal spasm in the small blood vessels (arteries or capillaries) which supply blood carrying oxygen to the skin. This effectively decreases blood flow to the body’s tissues, leaving extremities feeling ice cold to the touch.
Vasospasm episodes lead to a series of discolouration in these portions of the body, particularly when exposed to certain triggers (e.g. changes in temperature and intense emotions, such as stress). Discolouration typically happens in stages (a three-phase sequence of colour), initially turning white (due to interrupted or restricted blood flow), then blue (due to a prolonged lack of oxygen), and finally a red / flushed colour (when blood vessels re-open or dilate).
Most with Raynaud’s have a sensitivity to cold temperatures, and typically experience the three-phase colour changes as a result of exposure (and not just during the colder months of the year). In a sense, the body experiences an exaggerated reaction to ambient temperature change or stress triggers. Normally when exposed to cold temperatures, small blood vessels which circulate blood to the skin (known as thermoregulatory vessels) naturally narrow (to conserve warmth by minimising the amount of heat lost in the skin), and those further inside the body open to allow for more warmth, conserving the core temperature (internal temperature). This function becomes exaggerated in the case of Raynaud’s whereby more blood flow is restricted than is actually necessary with sudden and intense spasmodic contractions. Extreme narrowing of the blood vessels is known as vasoconstriction and results in what is known as a hyperactivation of the sympathetic nervous system.
During the white (also known as pallor) and blue (cyanosis) discolouration stages, extremities may feel numb and very cold (ice cold), sometimes painful (sensory nerves become irritated due to a lack of oxygen). The affected areas are unable to receive sufficient oxygen carried by the bloodstream (this is known as hypoxia). During the red (also known as rubor) stages, a throbbing, prickling or tingling sensation may be felt as blood flow begins to return and circulation is restored (dilation of arterioles). Colour and uncomfortable sensations do tend to return to normal soon after ‘an attack’ (i.e. the symptoms are only temporary). A Raynaud’s ‘attack’ (known as a vasospastic / vasospasm attack) can happen within a matter of minutes or last up to an hour (or longer if severe). Over time, small arteries can begin to thicken a little, which can lead to further restriction of blood flow.
Although uncomfortable during ‘an attack’, Raynaud’s is not considered a disabling condition. For many, it is more of a nuisance which can have some degree of effect on a person’s quality of life. It appears that more females are affected by the condition than males (9 times more), but it can occur any anyone of any age.
Did you know? A French physician, Dr Maurice Raynaud is credited with ‘discovering’ this condition following a report he published in 1862 documenting his findings about a woman whose fingertips experienced discolouration when she was under stress or cold. Hence the name, Raynaud’s syndrome / phenomenon, or disease.
There are two main types of Raynaud’s
As a condition, Raynaud’s can occur on its own or as a result of other conditions (provoked by similar vasospasms), such as arthritis, lupus, scleroderma (hardening and scarring of the skin) or even frostbite. Alone (without any other related medical conditions), the condition is diagnosed as ‘Raynaud’s disease’ (or primary Raynaud’s phenomenon) and is typically more common (making up the majority of cases). When accompanied by other underlying illnesses, Raynaud’s syndrome or Raynaud’s phenomenon is diagnosed as ‘secondary Raynaud’s phenomenon’ and often appears to be more severe, although it occurs less often.
- Primary Raynaud’s: Symptoms may be described as uncomfortable or painful, but not necessarily disabling. Symptoms experienced may prompt a person to adjust their lifestyle a little to minimise triggers which cause attacks. Primary Raynaud’s appears to occur in more women than men, usually between the ages of 15 and 30, in those who reside in colder climates and is suspected to run in families (it is more prevalent if a parent or sibling has the condition too). The majority of Raynaud’s cases (up to 90%) are primary. It is estimated that only 1 in 5 feel their symptoms may require medical diagnosis and seek out treatment. The others may simply put their symptoms down to ‘being cold-sensitive’ or merely having ‘poor circulation’.
- Secondary Raynaud’s: Symptoms of Raynaud’s may be the first signs of an underlying connective tissue condition (of a rheumatic nature). The collection of rheumatic-related symptoms may worsen those of Raynaud’s, placing a person at greater risk for further complications, such as long-term blood vessel damage (thickening), skin ulcers and even gangrene. Treatment for secondary Raynaud’s is typically focussed on alleviating symptoms of the underlying disorder which aggravates the condition. Symptoms commonly appear later in life than those of primary Raynaud’s (during a person’s 30s or 40s).
What causes Raynaud’s?
A definite underlying cause is still largely unknown to those in the medical field, especially when the condition is not associated with any other illness. A secondary form of Raynaud’s syndrome can be traced back to specific underlying conditions or lifestyle habits that adversely affect the function of blood vessels and impact connective tissues.
Research studies point to abnormal nerve control of the diameter of blood vessels and a nerve sensitivity to cold temperature as the primary causes of the condition.
Some underlying problems associated with secondary Raynaud’s include:
- Autoimmune / connective tissue conditions – rheumatoid arthritis, lupus, scleroderma or Sjogren’s disease.
- Conditions associated with hormone imbalances - Hypothyroidism or carcinoid tumours.
- Blood disorders - Cryoglobulinemia (excess proteins in the blood that become insoluble at lower temperatures) or polycythemia (elevated numbers of red blood cells in the blood).
- Medication use – beta-blockers and amphetamines are known to cause a narrowing of arteries. Birth control pills (oral contraceptives) are also known to influence blood flow. Other medications linked to Raynaud’s include migraine drugs containing ergotamine or sumatriptan, as well as some chemotherapy, some ADHD (attention deficit hyperactivity disorder) medications, and over-the-counter cold remedy drugs.
- Atherosclerosis – a condition that occurs due to a hardening of the arteries (plaque build-up in the blood vessels).
- Other associated diseases of the arteries – Buerger’s syndrome (inflammation in the hands and feet) and primary pulmonary hypertension (high blood pressure which affects the arteries of the lungs and right side of the heart) can also lead to Raynaud’s-like symptoms.
- Carpal tunnel syndrome – Raynaud’s-like symptoms can develop as a result of pressure on the nerves connecting to the hand (median nerves). This can result in pain or numbness in the hands, priming them for more frequent Raynaud’s attacks.
- Smoking (can narrow or constrict the arteries) and caffeine intake (may be a possible trigger)
- Bodily injury – fractures of the wrist or ankle, frostbite or following surgery.
For the most part, primary Raynaud’s has no known or related cause. Both forms of the condition however, are similar in that comparable types of triggers result in symptomatic attacks.
The most common triggers include:
- Cold temperatures (exposure through air, placing a portion of the body in cold water or contact with ice)
- Intense emotions or emotional stress (even without exposure to cold temperatures)
- Using hand tools which emit vibrations (e.g. jackhammers can increase a person’s risk for vasospasm)
- Repetitive motion such as those used for playing a musical instrument (piano or guitar) or typing
Associated influences (which may be a combination of contributing factors) for Raynaud’s syndrome include:
- Vascular mediators: Nitric oxide (a strong vasodilator that is more common in people with secondary Raynaud’s), endothelin-1 (a strong vasoconstrictor / protein than is more common among those with primary Raynaud’s) and serotonin (a neurotransmitter which occurs in higher concentrations in those with Raynaud’s).
- Oxidative stress: An increase in free radicals may be associated with Raynaud’s.
- Platelet activation: Components of blood which clump together in order to prevent bleeding has been noted as higher in those with Raynaud’s.
- Fibrinolysis: This is a natural process which takes place to reduce clotting in the body (breaking down of clots). Some studies have suggested that those with Raynaud’s have reduced levels of this process.
What are the signs you may have Raynaud’s?
Signs and symptoms
- Three-phase discolouration (white, blue, red)
- Sensation changes (numbness, ice cold, pain and tingling / stinging / prickling) – these may be mild or severe
- A little swelling (as circulation is being restored)
During a vasospasm, colour and sensation (or lack of) are the primary characteristic symptoms of Raynaud’s, mainly affecting the hands, feet, fingers and toes. For the majority, Raynaud’s symptoms affect the hands and fingers only. Up to 40% of those with the condition will experience symptoms in the feet and toes, as well as the hands. In some instances, the nose and ears, and even the lips or nipples can experience symptoms too (this is rare).
Those with primary Raynaud’s may note that an attack affects the same fingers and toes, often at the same time, on both sides of the body. Secondary Raynaud’s attacks may affect one or both sides (hands and feet, fingers and toes). Vasospasm attacks are not necessarily all that predictable, however, even in the same person. Episodic attacks may vary with each occurrence and not everyone will experience all three discolouration stages (some may experience white and then red for instance). Mild or brief temperature changes can bring on a vasospasm attack, but most will experience symptoms when exposed to temperatures below 15 degrees Celsius (60 degrees Fahrenheit).
A vasospasm attack can happen daily or even weekly, usually beginning with one finger or toe, and then gradually affecting other portions of the hands or feet. Attacks are not always a predictable pattern, however. Sometimes, only one finger or toe is affected at a time.
At the tail end of a vasospasm, affected areas may begin to throb a little as the red ‘flushed’ colour appears. At this stage, the body is beginning a re-warming process as circulation restores and it can take at least 15 minutes or more for warm sensations to return (blood flow remains low for a short period until the skin gradually rewarms) as blood flow to the skin returns to normal. One attack can take a few minutes, while others may last a little longer (up to an hour or so).
If Raynaud’s is suspected or a sore or infection appears to occur in the fingers or toes, it is best to consult a medical doctor for a thorough assessment. If there is an underlying condition of a rheumatic nature, it is wise to have this diagnosed and sufficiently treated in order to alleviate risk of long-term complications or ailments.
Risk factors and potential complications
Risk factors for Raynaud’s include:
- Gender: Women are more likely to develop Raynaud’s. More research studies are required to determine all possible causes related to this.
- Age: Onset of primary Raynaud’s often occurs in adults under the age of 30. Secondary Raynaud’s is more common in those over the age of 30 with the onset of symptoms typically becoming noticeable later.
- Family history: Risk does tend to increase if a first-degree relative (parent or sibling, and even a child) has the condition. As many as a third or primary Raynaud’s cases have a first degree-relative with similar symptoms.
- Climate: Colder geographical areas of the world tend to have more instances of Raynaud’s, than do those with warmer climates (although it is not impossible for Raynaud’s symptoms to develop in warmer areas of the world).
- Secondary Raynaud’s risk factors: Associated diseases and conditions, repetitive vibrations and exposure to substances such as medications (including those used in chemotherapy treatments), chemicals (vinyl chloride often used in the plastics industry) and smoking habits are all linked to secondary Raynaud’s phenomenon. Oestrogen without additional progesterone is also linked with the onset of Raynaud’s symptoms.
What possible complications can occur?
Raynaud’s is not classified as potentially life-threatening at all. Primary Raynaud’s typically has a lower risk of long-term complications due to the fact that no other underlying illnesses are present in the body.
If any symptoms worsen, however, blood supply can become considerably restricted in the long-term (i.e. blood circulation can permanently diminish). This can lead to skin ulcers (if oxygen supply is completely cut off from affected areas), gangrenous tissue and deformities in the fingers and toes.
It rarely happens that symptoms for Raynaud’s becomes severe, but if ulcers and gangrenous tissues occur, and attempts to treat these fail, amputation may be necessary.
Which medical professionals are best to consult with?
- General practitioners (GPs or family physicians)
- Hand surgeons / specialists (often with certified training in other specialised areas, such as orthopaedic surgery, plastic surgery, or general surgery)
The doctor’s visit
A consultation with a medical doctor will usually begin with a discussion regarding symptoms. Generally, a doctor will ask a series of questions in order to obtain as much detail and clarity about symptoms as possible. Some questions which are likely to come up may include:
- How long ago did symptoms begin?
- How frequently do symptoms (i.e. ‘attacks’) occur?
- Have any colour or sensation changes been noted in the affected areas? (Such as numbness or pain in the toes and fingers, or colour changes ranging from white, blue and red / flushed)
- Does anything specific appear to trigger symptoms?
- Is there a history of rheumatic illnesses in the family?
- Is there any member of the family with similar symptoms or a diagnosed Raynaud’s condition?
- Are any other medical conditions known to you? (I.e. have you been diagnosed with any other illness?)
- What medications or supplements have recently been taken (or are currently being taken)?
A doctor will also wish to gain some clarity on certain known triggers or symptom aggravators, such as caffeine use and smoking habits. Occupations or regular activities (i.e. recreational) may also be questioned to determine any potential repetitive movements which may be considered triggers or aggravators for symptoms of Raynaud’s.
Once enough information is obtained to use as a base for assessment, a doctor will conduct a physical examination of the affected areas of the body.
Testing for Raynaud’s syndrome
There is no single diagnostic test for Raynaud’s, but a doctor may recommend one or more so as to rule out any other underlying conditions which may be related to symptoms of the illness. In this way, testing may be used to make a diagnosis and determine the type or Raynaud’s present (i.e. primary or secondary). Testing may also largely depend on the symptoms present in the patient.
Tests can involve:
- A cold stimulation test: This test may be used as a way to trigger a vasospasm attack. A doctor may present a small temperature measuring device which will be attached to fingers or toes. Hands or feet will then be placed in ice water for several seconds and then removed. The exposure to ice cold conditions aims to trigger symptoms and then assess how long it takes for the skin to resume a normal body temperature using the measuring device. Although uncomfortable, the test poses no health risk to a patient and can be done immediately during a consultation. A doctor will assess discolouration changes, and discuss any sensations experienced as well. Temperature which returns to normal within 15 minutes is usually considered (reasonably) normal. Test results may be used in conjunction with any or all of the below evaluations.
- Capillaroscopy: This is a microscopic examination of the nailfolds (fingernails or toenails) and is commonly used to determine differences between primary and secondary Raynaud’s. Those with the secondary form of the condition typically have enlarged blood vessels or capillaries near the nailfolds (deformities can also be detected). Capillaries are typically ‘normal’ in those with primary Raynaud’s, when a vasospasm attack is not active. The test is often performed in the doctor’s office and could be used as a starting point for further testing should a doctor feel it necessary.
- Antinuclear antibodies (blood test): This blood test will help to determine primary from secondary Raynaud’s conditions by assessing the presence of ANAs (antinuclear antibodies), produced by the immune system, in the bloodstream. If these proteins are present (a sign of a stimulated immune system), it may be one indicative marker of an autoimmune or connective tissue condition.
- Erythrocyte sedimentation rate (ESR or sed rate test): Another blood sample can be analysed (in a laboratory) to determine the rate at which red blood cells settle into the bottom of a test tube. If this process of descending cells is determined as faster than normal (i.e. the standard rate), it could indicate a potential underlying rheumatic / inflammatory or autoimmune disorder (i.e. an elevated sed rate due to inflammation in the body).
- C-reactive protein blood test: CRP or C-reactive proteins are normally produced by the liver in response to inflammation in the body. A high-level present in the bloodstream may indicate inflammation in the arteries connecting to the heart or those associated with any other inflammatory condition, such as rheumatoid arthritis or lupus.
- Rheumatoid factor blood test: High levels of proteins produced by the immune system in the blood could indicate inflammatory conditions.
If testing does not show up any diagnostic markers for other associated conditions, it is likely that a doctor will diagnose primary Raynaud’s. If testing does present inflammation markers, it is likely that a doctor will look for (using a physical exam and appropriate testing) signs of other conditions. For instance, thickened skin could indicate scleroderma or a malar rash (‘butterfly shape’) characteristic of lupus.
Symptoms of Raynaud’s can develop years before an inflammatory condition. Thus, a doctor could diagnose primary Raynaud’s, but request periodic check-ups to monitor any possible condition developments. If any connective tissue disorders are suspected, it is likely that a GP or internist may recommend a Rheumatologist visit as these specialists typically have more knowledge and experience with these associated conditions.
Symptoms of Raynaud’s can be treated or significantly reduced, but not cured. As there is so much still to understand through clinical research regarding the cause of the condition, a cure is not yet available once diagnosed.
The biggest factor to take into consideration when it comes to treating Raynaud’s relates to lifestyle changes which prevent the constriction of blood vessels as much as possible. This is necessary so as to avoid as much damage to skin tissue as possible. By minimising the frequency and severity of attacks, risk for damage is kept relatively low. In most primary cases, lifestyle changes are all the treatment that is needed. In secondary Raynaud’s cases, treatment will focus on symptoms associated with underlying disorders or conditions, often including medications.
1. Lifestyle adjustments and considerations which may be mentioned by a doctor include:
- Avoiding triggers or aggravators such as smoking (including second-hand smoke) as this can lead to a hardening of the arteries (arterial disease). It is also best to limit alcohol and caffeine intake.
- Making efforts to stay as warm as possible at all times (all year round), especially the hands and feet. A drop in core body temperature can trigger a vasospasm attack. Headwear can help to minimise heat dissipation through the scalp (which helps to retain body heat). Dressing in layers may also make it easier to maintain ideal core body temperature. Polypropylene fabrics tend to keep moisture away from the body which can help to alleviate cooling. Clothing and footwear materials should be breathable and waterproof.
- Regular exercise can help to keep the body warm and also alleviate the intensity of a vasospasm attack by improving blood circulation and also helping to better manage stress. Windmill arm exercises (swinging the arms in circular motions at the sides of the body) can be good for getting blood circulation going. Those with secondary Raynaud’s are advised to consult their doctor before attempting exercise outdoors in very cold weather. He or she can advise the best options according to the underlying disorder and associated symptoms.
- Soaking affected portions of the body in warm (not hot) water during a vasospasm attack can alleviate some symptoms.
- Ensuring that room temperatures in the home and place of work are not too cool if spending a considerable amount of time in the environment. This includes maintaining a comfortable temperature using air conditioners during the warmer months of the year. It is also wise to be mindful of sharp temperature changes – i.e. moving from a warm room to bitterly cold outside temperatures. Dressing in preparation for these sorts of changes can help alleviate risk of an attack.
- Avoid walking around barefoot too often so as to avoid dissipation of heat. Wearing socks at night, especially during the winter can also help. Merino wool or cashmere are natural, soft fibres which are great for keeping feet warm at night. Compression socks, although made to improve circulation, are not an ideal choice when lying down (as these may block blood flow).
- Foot powders applied to the feet can help to absorb moisture, alleviating dampness which can cause cooling.
- Avoid wearing tight-fitting footwear, wrist-bands or rings which can aggravate blood vessel constriction in the hands, feet, fingers and toes. Tight-fitting clothing should also be avoided.
- Take precautions when exposing affected portions of the body to temperature changes – use gloves when washing dishes or taking things out of a freezer.
- Where possible, especially when stress appears to trigger or aggravate symptoms, measures to reduce levels are advisable.
2. Medical treatment
- Medications: Severe symptoms (i.e. intense vasospasm attacks which are long-lasting and / or frequent) can be treated with medication. Medications may be prescribed to relax blood vessels and thereby reduce attacks. Medication types a doctor may prescribe to help with this include vasodilators such as antidepressants, erectile dysfunction drugs or those used for antihypertension, as well as blood thinners (such as aspirin). An alpha blocker (alpha-1 blocker) can help to counteract the hormone norepinephrine, which can constrict blood vessels. A calcium channel blocker can also be prescribed to help increase blood flow to affected areas and heal skin ulcers. Medications which a doctor may limit or recommend avoiding altogether as they can worsen blood vessel constriction include oestrogen-based drugs, oral contraceptives (birth control pills), migraine medications, beta-blockers and pseudoephedrine-based medications for the treatment of colds, coughs or allergies. A topical nitroglycerin ointment can help to relax or widen blood vessels and can be prescribed for application on affected portions of the body for relief (i.e. improving blood flow). Before any medications are used, associated side-effects must be discussed with a doctor before commencing dosages. Some medications may not be taken during pregnancy due to their potentially adverse effects on a growing baby.
- Surgery: Where all else fails and symptoms are debilitating or causing a severe lack of blood circulation, a doctor may consider a sympathectomy procedure (or digital sympathectomy). This is a surgical procedure which works to interrupt the exaggerated response in the sympathetic nerves of the hands and feet. Small incisions (usually along the sides at the base of a hand or foot) help to better control the opening and closing (dilation and constriction) of tiny blood vessels in the skin by removing nerves around the capillaries (this is known as adventitial stripping). The aim is to reduce the intensity, frequency and duration of vasospasm attacks, but this is not always successful. Results can sometimes only provide temporary relief. It is best to weight up benefits and risks with the surgeon before opting to try the procedure. Generally, surgery is reserved for particularly complicated or severe conditions.
- Chemical injections: An alternative to surgery may involve frequent injections using local anaesthetics or onabotulinumtoxin type A (botulinum toxin type / botox). Injections may provide temporary relief by targeting the sympathetic nerves, effectively relieving constriction of the blood vessels / capillaries in the hands and feet. Benefits versus risks should also be discussed with the treating doctor before opting to commit to this route of treatment.
Living with Raynaud’s
Without a cure, managing symptoms and vasospasm attacks requires long-term commitment and consideration. Treatment measures are ongoing, requiring a daily effort to alleviate or prevent symptoms.
Symptoms may improve with daily care, and very rarely worsen. Simple adjustments can make all the difference. The majority of those with primary Raynaud’s respond well to lifestyle adjustments and considerations. Moderate to severe cases can also respond well to medication treatment options.
If a doctor has requested periodic follow-ups, it is advisable to keep these appointments, ensuring that any, and all symptom changes are appropriately checked, monitored or treated. Any worsening symptoms or the development of new ones should always be checked by a medical professional.
What to do in the event of a vasospasm attack
Warm up affected areas such as the hands and feet by doing the following:
- Seek out a warmer environment: If outside, find a warm spot indoors or move away from cold fans and air conditioners.
- Promote improved blood circulation: Wiggle the fingers and toes about, place hands under armpits or perform windmill exercises with the arms to encourage circulation to the fingers. Massaging the hands and feet can also help, as can running warm (not hot) water over affected areas.
- Remove stress triggers: If a vasospasm attack is triggered by stress, where possible, find ways to step away from a situation or environment and relax.
Alternative symptom management
Some supplements may help to enhance blood circulation in the body, which in turn can assist with alleviating the frequency or intensity of vasospasm attacks. More research studies are being done in this area, so it is advisable to consult a treating medical doctor for advice and the most up to date developments before taking any supplements (even if natural or herbal), especially if medications are already being used (so as to avoid adverse interactions and side-effects).
One such option to try are fish oil supplements. Some research has indicated that fish oil can help to improve tolerance to cold temperatures and also alleviate inflammation. Fish oil can act like a blood thinner, which can help to dilate blood vessels that are prone to narrowing.
Another substance which may be beneficial is ginkgo biloba. Studies have linked this tree species with potential medicinal properties as it has long been associated with traditional medicine use for circulatory and respiratory problems. Ginkgo can help to naturally increase blood flow by thinning out the blood and dilating capillaries (blood vessels). Some studies have indicated that regular use of ginkgo can significantly reduce the frequency of vasospasm attacks. Ginkgo supplements should never be taken in combination with other blood thinners as this can increase risk for internal bleeding.
Other alternative treatment options which have been, and continue to be studied as possible symptom relievers include thermal biofeedback and acupuncture. Once again, before trying any alternative healing practices, it is best to consult a medical doctor to assess possible benefits versus risks.
What is the outlook for Raynaud’s?
Generally, a person’s outlook for Raynaud’s is dependent on the intensity of their condition and the type. Primary Raynaud’s does not generally pose many additional health concerns and when mild is more of a nuisance than a debilitating condition. There is very little risk of long-term damage or disability.
Secondary Raynaud’s is associated with higher risk factors of infection, ulcers of the skin affecting the hands and feet and in severe cases, gangrene. Other risk factors may be associated with underlying cause conditions. Prolonged or frequent vasospasm attacks that are severe can lead to some degree of long-term damage.
Ongoing treatment and lifestyle considerations are important so as to avoid tissue damage to the skin and blood vessels in the body. A person can cope fairly well with the condition, with or without the aid of medications. The less frequently vasospasm attacks occur, the better in the long run.
The more precipitating factors can be avoided or limited, the easier it can be to prevent frequent attacks.
What kind of research is being done on Raynaud’s?
Research studies are looking at possible links relating to causes of the condition. As yet, causes of the condition are not as understood as the trigger points of the condition. Suspected influences being researched include:
- Genetics (inherited factors) and molecular mechanisms as they relate to symptoms and other associated blood-vessel changes.
- Nitric oxide used in a gel form is being looked at as a possible circulation treatment (local nitric oxide may help to dilate blood vessels).
- Techniques which may be better to help make a diagnosis, and monitor treatment responsiveness.
Researchers are also looking into the condition in relation to associated secondary disorder influences (connective tissue diseases and other rheumatic or autoimmune conditions).
1. National Heart, Lung and Blood Institute. 21 March 2014. What is Raynaud's: https://www.nhlbi.nih.gov/health/health-topics/topics/raynaud [Accessed 03.08.2017]
2. National Institute of Arthritis and Musculoskeletal and Skin Diseases. October 2016. Questions and Answers about Raynaud’s Phenomenon: https://www.niams.nih.gov/Health_Info/Raynauds_Phenomenon/default.asp [Accessed 04.08.2017]