Raynaud's phenomenon - Causes of Raynaud's

Raynaud's phenomenon is the result of over-sensitive blood vessels in the body's extremities. In many cases, no cause is identified, although it is sometimes linked to other health conditions.

When your body is exposed to cold temperatures, the extremities, such as your fingers and toes, lose heat. This is because the small blood vessels under the skin spasm, slowing down the blood supply that helps to preserve your body's core temperature.

In people with Raynaud's, the sensitive blood vessels overreact to cold temperatures and narrow much more than usual, significantly restricting the blood flow.

Symptoms can be triggered by mildly cool weather, getting something out of the freezer, or running your hands under a cold tap. Strong emotions such as stress or anxiety may also trigger symptoms. Read more about stress, anxiety and depression.

Primary Raynaud’s

The most common form of Raynaud's is primary Raynaud's phenomenon. This means the condition occurs by itself, without being associated with another health condition.

It seems that primary Raynaud’s is caused by disruptions in how the nervous system controls blood vessels. Exactly what causes these disruptions is still unclear.

There is some evidence that Primary Raynaud’s may be an inherited condition as cases have been known to run in families.

Secondary Raynaud's

In some cases, there is an underlying reason, usually a health condition, that causes the blood vessels to overreact. This is called secondary Raynaud's.

Autoimmune conditions

The majority of cases of secondary Raynaud’s are associated with what are known as autoimmune conditions. These are conditions that cause the immune system to attack healthy tissue, causing a range of symptoms such as redness and swelling in the affected area.

Autoimmune conditions known to be associated with secondary Raynaud’s include:

• scleroderma: a condition that causes hardening and thickening of the skin
• rheumatoid arthritis: which causes joint pain and swelling
• Sjogren's syndrome: where the immune system attacks the body’s sweat and tear glands
• lupus: which causes tiredness, joint pain and skin rashes

Around one in 10 people with primary Raynaud’s go on to develop an autoimmune condition.

Infections

Two blood-born viral infections, hepatitis B and hepatitis C, can occasionally trigger Raynaud’s in some people.

Cancer

Some types of cancer can cause secondary Raynaud’s. These are usually cancers that develop inside the blood, bone marrow or immune system, such as:

• acute lymphoblastic leukaemia: a cancer of the white blood cells that mainly affects children
• lymphoma: a cancer that develops inside one or more of the glands that are part of the immune system
• multiple myeloma: a cancer that develops inside bone marrow

Medicines

Secondary Raynaud's can also be a side effect of taking certain medicines, including:

• some types of anti-migraine medication, such as sumatriptan and ergotamine
• beta-blockers, which are used to treat high blood pressure and heart disease
• some chemotherapy medications
• decongestants 
• the contraceptive pill
• medications used in hormone replacement therapy
• some types of medications used in the treatment of high blood pressure, such as angiotensin-converting enzyme (ACE) inhibitors and clonidine

The illegal drugs cocaine and amphetamines can also cause secondary Raynaud’s.

Injury and overuse

Raynaud's sometimes results from a physical injury to the affected area. It can also affect musicians, people who type a lot or other people who use their fingers and hands more than usual.

Vibration white finger

Vibration white finger is a term used when secondary Raynaud's has been caused by exposure to vibration. This typically happens to people who regularly use certain types of vibrating tools, such as: 

• sanders, grinders and disc cutters
• hammer drills
• chainsaws, hedge trimmers and power mowers

Any vibrating tool that causes tingling or numbness in your fingers after five minutes of continuous use could lead to vibration white finger.

Your employer has a responsibility to protect you from vibration white finger. You could get help from your employer by asking if the job could be done without using vibrating tools. If this is not possible:

• ask to use suitable low-vibration tools
• make sure you are using the right tool for the job
• check tools are properly maintained
• keep cutting tools sharp
• reduce the amount of time you use the tool in one go by doing other jobs in between
• keep warm at work
• wear anti-vibration gloves
• store tools indoors so they do not have cold handles when next used
• encourage your blood circulation by keeping warm, stopping smoking and massaging and exercising your fingers during your breaks

If you are diagnosed with vibration white finger, tell your employer as soon as possible. If you stop using vibrating tools at an early stage of the condition, you may recover fully.

By law, your employer must contact the Health and Safety Executive about your condition. You may be entitled to an Industrial Injuries Disablement Benefit, which is a payment given to people who have become ill or injured as a result of their work.

See the GOV.UK website for more information about the Industrial Injuries Disablement Benefit.