Vomiting in cats can be caused by minor stomach upset, hairballs or a more serious medical condition. Vomiting should not be confused with regurgitation. Cats that eat too fast may regurgitate undigested food. Vomiting involves foods and acids that are coming back up from the stomach and the process usually includes retching and heaving. One of the most common reasons that a cat throws up is due to food allergies or intolerances. Cats can be allergic to meat proteins or a carbohydrate ingredient in their food. Diet changes, ingestion of a foreign object and parasites can also trigger vomiting. If your kitty is throwing up frequently, you should see your vet to determine if the vomiting is a symptom of a more serious condition such as hyperthyroidism, kidney disease, IBD, cancer or pancreatitis.