Summarize this article:

Foreign bodies can get lodged in the nose, throat, trachea, or bronchi of a cat, and the symptoms vary depending on the exact location of the foreign object. Look for any of the following symptoms:  Nasal discharge Sneezing Nose-pawing or nose-bleeds Head shaking Gagging Salivation Difficulty swallowing or breathing Bad breath Pawing at the face and mouth Coughing Retching Blue coloured gums Fainting Anorexia In most instances a foreign body, such as a blade of grass or a piece of a stick, will enter your cat while they are smelling or chewing these objects. Keep a close eye on your cat while it is playing outside. This way you will have a better indication of what might be the problem if your cat starts to develop symptoms. If you notice any common symptoms associated with a respiratory foreign body, or you believe your cat may have inhaled a foreign object, you should take your cat to the vet immediately. If left untreated, a foreign body in the respiratory system could cause an infection or lead to chronic lung disease. In some cases the foreign object may travel through the body, causing severe complications and even death. Your vet will need to run a number of tests in order to rule out other possible illnesses and to find the exact location of the foreign object. Your vet will likely need to administer a number of examinations in order to determine the exact location of the foreign object. An examination can also provide your vet with more detailed information concerning the type of object that has been lodged in the respiratory system. Your vet may administer any of the following tests:  A complete blood count (CBC), biochemical profile, and urinalysis. An x-ray of the throat and chest. Skull/nasal radiographs. A scope may be used to evaluate the nasal cavity, trachea, and bronchi. A CT Scan or MRI may be useful in some cases.

Summary:
Notice common symptoms. Monitor your cat while outside. Take your cat to the vet. Have your cat examined.