Acute Bronchitis: This is often the most common cause of a dry cough lasting for 2 weeks, especially in the absence of other symptoms. It's usually viral in nature and self-limiting.

Postnasal Drip (Upper Airway Secretion Syndrome): This condition can cause a dry cough due to the irritation of the throat from nasal secretions draining down.
Asthma: Cough can be a sole presenting symptom of asthma, especially if it's mild or if the patient has cough-variant asthma.
Gastroesophageal Reflux Disease (GERD): Stomach acid reflux can irritate the throat and cause a dry cough.
Allergies: Allergic reactions can lead to a dry cough, especially if the individual is exposed to specific allergens.

Pulmonary Embolism: Although less likely, a dry cough can be a symptom of a pulmonary embolism, which is life-threatening and requires immediate medical attention.
Lung Cancer: A persistent dry cough can be an early symptom of lung cancer, making it crucial not to miss this diagnosis, especially in smokers or those with a significant smoking history.
Tuberculosis (TB): TB can present with a chronic dry cough among other symptoms, and it's essential to consider this diagnosis, especially in individuals who have been exposed or are from areas with high TB prevalence.
Pneumonia: While typically accompanied by other symptoms like fever and shortness of breath, pneumonia can occasionally present with a dry cough, especially in its early stages or in certain populations like the elderly.

Sarcoidosis: A systemic disease that can affect the lungs and cause a dry cough, among other symptoms.
Interstitial Lung Disease: A broad category of diseases that affect the lung tissue and can cause a dry cough.
Eosinophilic Pneumonia: A rare condition characterized by an accumulation of eosinophils in the lungs, which can cause a dry cough.
Histiocytosis X (Langerhans Cell Histiocytosis): A rare disorder that can affect the lungs and cause respiratory symptoms, including a dry cough.