Gastroesophageal Reflux Disease (GERD): This condition is characterized by the reflux of stomach acid into the esophagus, which can irritate the throat and trigger coughing. Laughing deeply can increase abdominal pressure, promoting reflux. The absence of dysphagia, odynophagia, and weight loss does not rule out GERD, as many patients with GERD may not exhibit these symptoms.

Chronic Obstructive Pulmonary Disease (COPD): COPD can cause a chronic cough, and laughing can exacerbate symptoms due to increased respiratory rate and depth, leading to airway irritation.
Asthma: Similar to COPD, asthma can cause coughing that worsens with laughter due to bronchospasm triggered by the increased respiratory effort.
Postnasal Drip: Also known as upper airway secretion syndrome, this condition can cause a chronic cough. Laughing can increase nasal secretion or alter respiratory patterns, exacerbating the cough.

Lung Cancer: Although less likely, it is crucial not to miss lung cancer, especially in a 71-year-old patient. Coughing induced by specific actions like laughing could be a symptom, although it's more commonly associated with persistent cough, weight loss, and other systemic symptoms.
Pulmonary Embolism: While unlikely to present solely with cough induced by laughter, pulmonary embolism is a life-threatening condition that must be considered, especially if there are other risk factors or symptoms such as chest pain or shortness of breath.
Cardiac Conditions (e.g., Heart Failure): Certain cardiac conditions can lead to coughing, especially if there is pulmonary congestion. Laughing could potentially exacerbate this due to increased venous return and cardiac workload.

Vocal Cord Dysfunction: This condition can mimic asthma and cause coughing and wheezing, especially with specific triggers like laughing.
Tracheoesophageal Fistula: An abnormal connection between the trachea and esophagus, which could potentially cause coughing when laughing due to the passage of food or liquid into the airway.
Eosinophilic Esophagitis: An inflammatory condition of the esophagus that can cause dysphagia and food impaction but might also lead to coughing in some cases, especially if there's an association with allergic reactions or irritants.