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's 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 is helping to preserve your body's core temperature.
In people with Raynaud's, the sensitive blood vessels overreact to cold temperatures and become narrower 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.
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 unclear.
There's some evidence that primary Raynaud’s may be an inherited condition, as cases have been known to run in families.
In some cases, an underlying health condition could be causing the blood vessels to overreact. This is called secondary Raynaud's.
The majority of cases of secondary Raynaud’s are associated with autoimmune conditions, which cause the immune system to attack healthy tissue.
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 1 in 10 people with primary Raynaud’s go on to develop an autoimmune condition.
Blood-born viral infections, hepatitis B and hepatitis C, can occasionally trigger Raynaud’s in some people.
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
Secondary Raynaud's can also be a side effect of taking certain medicines, including:
Illegal drugs, such as cocaine and amphetamines, can also cause secondary Raynaud’s.
Injury and overuse
Raynaud's sometimes results from a physical injury. It can also affect musicians, people who type a lot, or other people who use their fingers and hands more than usual.
Skin and tissue damage caused by frostbite can also lead to Raynaud's.
Smoking cigarettes also increases your risk of developing Raynaud's. Read about the support available to help you quit smoking.
Vibration white finger
Vibration white finger is a term used when secondary Raynaud's has been caused by 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 could lead to vibration white finger.
Your employer has a responsibility to protect you from vibration white finger. If the job can't be done without vibrating tools:
- ask to use suitable low-vibration tools
- make sure you're 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 don't 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're diagnosed with the condition, tell your employer as soon as possible. If you stop using vibrating tools at an early stage, 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.