Question about my cat?

Yesterday my cat was acting completely normal. Today i noticed that my cat didnt come up from the basement at all so i went and got her at about 4 o clock. She coughed 1 time before i brought her up. I sat her down upstairs and she has not left that spot at all. She sits up alot and seems like she is dizzy. She has also made a squeaking sound followed by what looks like swallowing. She seems to squint alot when i go over to her. By the way she is 10 years old. What could possibly be wrong with my cat?