Have you checked your pinky for deformities lately? Go ahead, we'll wait....
If you noticed a dent or curve in your pinky finger and you own a smartphone you may have 'smartphone pinky' from holding your phone too much.
Great, one more thing to worry about.
Except, don't worry about this. Your pinky finger is probably totally normal.
According to Popular Science, it's most likely a natural curve of the pinky that a lot of people have or a dent that will go away just like the lines on your face after sleeping face down on your pillow. At worst, it could be a repetitive strain injury from something other than just holding your phone but you would probably know the difference because your pinky would likely also be in pain. In which case you should see a doctor, but not because your smartphone is deforming you.