A cold stimulation test is used to diagnose Raynaud’s phenomenon.
When blood flow is blocked, an area may first turn white and then blue. You may feel numbness or pain. When normal blood flow returns, the area turns red. Eventually it goes back to a normal color.
The duration of episodes ranges from minutes to hours.
Primary Raynaud’s happens on its own. It is not caused by injury, medication, or disease. This type is usually seen in people under 30 years of age.
Secondary Raynaud’s occurs because of another disease, cause, or medication. This type is most often found in people over 30 years of age.
Some causes of secondary Raynaud’s include:
- artery diseases, such as Buerger’s disease or atherosclerosis
- medications that narrow the arteries, such as some beta-blockers, certain cancer drugs, amphetamines, methysergide, and ergot compounds
- autoimmune conditions, such as rheumatoid arthritis, lupus, and scleroderma
- repeated injury to the arteries, especially from activities that cause vibration
- thoracic outlet syndrome
The test is designed to trigger symptoms of Raynaud’s. It is used along with other tests to diagnose the condition.
The test takes several steps:
- A small temperature-measuring device is attached to your fingers with tape.
- Your hands are exposed to cold by putting them briefly into ice water.
- Your hands are removed from the cold water.
- The measuring device records how long it takes your fingers to return to normal body temperature.
The test may cause some mild discomfort. However, there are no risks associated with the test.
No specific preparations are needed for the test.
Finger temperature will generally return to normal within 15 minutes.
If it takes longer than 20 minutes for your fingers to return to normal body temperature, you may have Raynaud’s.