My cat is vomitting

My 17year old cat is vomiting up a lot of his food every few days..sometimes daily.  I cannot tell if it's because of hairballs. Sometimes it includes hairballs, somtimes not.
Does anyone know what might be wrong with him.

He also sneezes a lot and has a runny nose.

Worried.

[Aleda M Cheng, D.V.M., C.V.A]

There are many causes of vomiting in aged cats including: hyperthyroid, Inflammatory bowel disease, constipation, food allergies, gastrointestinal parasites, urinary tract infections, gastrointestinal cancer, and more.  

Your cat has not been to the vet for over a year.  That is seven years in humans and a lot can change in 7 years.  Please take your cat back to the vet and have blood work including thyroid testing, and a urinalysis.  If your cat is dehydrated and is only eating dry food please allow your vet to give subcutaneous fluid therapy and eliminate dry kibble and feed wet only.  If your cat is constipated, wet food will help to hydrate the bowel.  Your vet can give appropriate treatment once definitive diagnosis is made.

[leopard19]

Will do!  Thanks for the info.  And he does prefer wet food to dry food lately.