Another easy way to test if your skin is dehydrated is to press your nail bed. If it turns white and when you release the pressure, the blood rushes back. If your skin is dehydrated, your nail bed takes longer to become pink or reddish again. 1. Hold your hand (where you will do the test) right above your chest. 2. Pinch the nail bed with your other hand until it becomes fully white. 3. Release the pressure. 4. Observe how many seconds it takes to normalize again or turn to pink again