A little everyday story: cold palms in winter
Imagine a cold winter night. Xiao Ming rides his scooter home, and his hands turn pale and stiff from the cold. He clenches his fists hard and then relaxes them, and finds that his palms change instantly from white back to a healthy pink.
This “return of color” happens because blood flows quickly back into the palm through the radial artery and the ulnar artery. In hospital, when a physician prepares for cardiac catheterization, they press on the upper “radial artery” and watch the reading on a fingertip pulse oximeter. If the reading keeps pulsing steadily, it shows that Xiao Ming’s “second pipe (the ulnar artery)” is strong and the procedure is very safe.
The “double insurance” in your palm
Our palms are in fact born with two supply pipes (blood vessels) that complement each other. When one needs to be taken out of service, the other automatically steps in to help. This is exactly the principle behind the medically important Barbeau test.
The palm’s two-way supply system
- Upper main line: the radial artery Located on the thumb side, it is the main place to take the pulse and feel the heartbeat.
- Lower line: the ulnar artery Located on the little-finger side, it quietly serves as your second, back-up supply line.
- Central ring: the palmar arch The two arteries meet in the palm and form a ring, so that the two supplies support each other.
The Barbeau test: “data-based evidence” for safety
Unlike the traditional Allen’s test, which relies on visual inspection, modern medicine uses the pulse oximeter waveform, so that the judgment rests on data rather than subjective impressions.
- Waveform keeps pulsing steadily: the automatic back-up system works perfectly and the procedure is safe.
- Waveform disappears: your palm relies more on a single supply, and your physician will choose a safer alternative route for you.
See what specialist physicians do (links to clinical evidence)
(reference: Terumo Interventional Systems youtube channel)
Everyday care and suggestions for improvement
Although your vessels are born with double insurance, keeping them elastic and open is still essential:
- Keep your hands warm: in winter or in an air-conditioned room, if your hands often feel cold and pale and have no wounds, you can soak them in warm water to promote peripheral circulation. Gloves or hand warmers can also help keep them warm.
- Hand stretching exercises: making a fist and then opening the hand forcefully is recommended to promote circulation in the palm.
- Quit smoking and eat a low-fat diet: blood vessels are most vulnerable to nicotine and excess fat deposits. Keeping the vessel walls clean and elastic is the best way to protect yourself.
