upstairs
n. placen. on or to a higher floor of a building. You use this when you are moving toward the top of a house or talking about what is above you.
n. situated on or relating to an upper floor of a building. Functions as a locative adverb or a post-positive adjective.
I am going upstairs to get my coat.
The children are playing quietly upstairs while the adults finish their dinner in the kitchen.
Although the ground floor remains relatively cool during the summer months, the heat tends to accumulate upstairs, making the bedrooms uncomfortable without proper ventilation.
From up- + stair + -s.
Typically functions as an adverb of place following a verb of motion or position; can also follow a noun as a post-modifier.
I am going to upstairsI am going upstairsUpstairs is an adverb of place and does not require the preposition 'to' when used with verbs of motion.