Some dogs have trouble navigating hardwood stairs. They slip as they are trying to climb or descend the stairs, and can actually fall down the steps.
To help your dog, you can apply rugs to the individual steps. Use double-sided carpet tape to apply the rugs. This will do two things.
First, it gives the dog enough traction to safely navigate the stairs. This allows the dog to feel more comfortable on the steps, which reduced the whining and crying they do at the bottom of the stairs when they want to come up.
Additionally, it will help to protect the hardwood on the stairs themselves. When the dog is slipping, it will use its claws to get a grip, resulting in scratches on your stairs. Also, dogs that are stuck at the bottom of the steps, wanting to come upstairs, might paw and scratch at the steps, damaging the wood.
Help your dog by covering the slippery hardwood stairs with stair tread rugs.Sarah - Information about stair tread rugs from http://stairtreadrugs.net