The pinch test is easy to do. It may help you compare the blood flow in an injured limb with an uninjured limb.

• Gently pinch one of the fingernails or toenails of the uninjured limb until the nail bed turns pale.
• Release the pinch.
• Watch closely to see how long the nail bed takes to regain its normal color.
• Repeat the steps on the injured limb.
• If the blood flow is the same in both the injured and uninjured limbs, the color of the nail beds will return to normal in the same amount of time.
• If the blood flow in the injured limb is not the same as in the uninjured limb, the color of the nail bed will take a few seconds longer to return to normal.
• Repeat the test if you are not sure of the results.

Decreased blood flow may be present if the nail bed color in the finger or toe of the injured limb takes longer to return to normal than in the uninjured limb.