my cat is very thin and has a bloody nose what's wrong with her?

Untreated medical conditions won't be helped by food and water. When a cat has a large amount of weight loss there's something severe going on and you NEED to get the cat in for a checkup.

Diabetic condition, kidney issues, thyroid problems and renal failure all cause fast weight loss. The first three are treatable, IF you don't wait on taking the cat in to get help. The longer you wait, the harder it is to stabalize the cat and get them back to normal. The fact she's bleeding from her nose is not good---I fail to see why nobody has considered this the vet emergency that it is. Get her in, get her checked!

If a cat is coughing, very thin and the nose is bleeding, that would indicate that the cat is very sick and needs to see a vet right away. The cat will die if not properly treated. That is what veterinarians do. That is why people take their pets to a vet, if a person is a responsible pet owner.

Just as the others have said, get the cat to a vet ASAP. If the cat hasn't been to a vet before, Banefield (at Petsmart) will do a free office visit and they are usually always open on Saturday and Sunday.

you need to take her to the vet asap

Hate to say it, but sounds like leukemia.

take her to the vet ASAP.