A lung cavity or pulmonary cavity is an abnormal, thick-walled, air-filled space within the lung. Cavities in the lung can be caused by infections, cancer, autoimmune conditions, trauma, congenital defects, or pulmonary embolism. The most common cause of a single lung cavity is lung cancer. Bacterial, mycobacterial, and fungal infections are common causes of lung cavities. Globally, tuberculosis is likely the most common infectious cause of lung cavities. Less commonly, parasitic infections can cause cavities. Viral infections almost never cause cavities. The terms cavity and cyst are frequently used interchangeably; however, a cavity is thick walled (at least 5 mm), while a cyst is thin walled (4 mm or less). The distinction is important because cystic lesions are unlikely to be cancer, while cavitary lesions are often caused by cancer.Diagnosis of a lung cavity is made with a chest X-ray or CT scan of the chest, which helps to exclude mimics like lung cysts, emphysema, bullae, and cystic bronchiectasis. Once an imaging diagnosis has been made, a person’s symptoms can be used to further narrow the differential diagnosis. For example, recent onset of fever and productive cough suggest an infection, while a chronic cough, fatigue, and unintentional weight loss suggest cancer or tuberculosis. Symptoms of a lung cavity due to infection can include fever, chills, and cough. Knowing how long someone has had symptoms for or how long a cavity has been present on imaging can also help to narrow down the diagnosis.
The characteristics of the behaviors associated with stealing could result in other problems as well, which include social segregation and substance use. The many types of other disorders frequently occurring along with kleptomania usually make clinical diagnosis uncertain.There is a difference between ordinary theft and kleptomania: "ordinary theft (whether planned or impulsive) is deliberate and motivated by the usefulness of the object or its monetary worth," whereas with kleptomania, there "is the recurrent failure to resist impulses to steal items even though the items are not needed for personal use or for their monetary value." Cause
Psychoanalytic models
Many psychoanalytic theorists suggested  that kleptomania is a persons attempt "to obtain symbolic compensation for an actual or anticipated loss", and feel that the key to understanding its etiology lies in the symbolic meaning of the stolen items. Drive theory was used to propose that the act of stealing is a defense mechanism which serves as to modulate or keep undesirable feelings or emotions from being expressed. Some French psychiatrists suggest that kleptomaniacs may just want the item that they steal and the feeling they get from  theft itself. Cognitive-behavioral models
Cognitive-behavioral models have been replacing psychoanalytic models in describing the development of kleptomania. Cognitive-behavioral practitioners often conceptualize the disorders as being the result of operant conditioning, behavioral chaining, distorted cognitions, and poor coping mechanisms. Cognitive-behavioral models suggest that the behavior is positively reinforced after the person steals some items.