Acute Bronchitis: This is often the most common cause of a cough lasting for a few weeks. It's usually caused by a viral infection and can be accompanied by other symptoms like runny nose, sore throat, and fatigue. The cough can persist even after the initial infection has resolved.

Postnasal Drip (Upper Airway Secretion Syndrome): This condition occurs when excess mucus from the nose drips down the back of the throat, triggering a cough. It can be due to allergies, a cold, or sinus infections.
Asthma: Cough can be a primary symptom of asthma, especially if it's exercise-induced or worsens at night. Other symptoms might include wheezing, shortness of breath, and chest tightness.
Gastroesophageal Reflux Disease (GERD): Stomach acid can flow up into the esophagus and irritate the throat, leading to a chronic cough. Symptoms can include heartburn, regurgitation, and difficulty swallowing.
Chronic Obstructive Pulmonary Disease (COPD): While more common in smokers, COPD can cause a persistent cough, often with sputum production. Other symptoms include shortness of breath and wheezing.

Pneumonia: Although less likely if the patient appears well, pneumonia can present with a cough and may not always have fever or severe symptoms, especially in the early stages or in older adults.
Lung Cancer: A persistent cough, especially if it's new, worsening, or accompanied by other symptoms like weight loss, hemoptysis, or unexplained fatigue, requires investigation for lung cancer, particularly in smokers or those with a significant smoking history.
Tuberculosis (TB): A chronic cough, especially with systemic symptoms like fever, night sweats, and weight loss, should prompt consideration of TB, especially in individuals from endemic areas or with risk factors like immunosuppression.
Pulmonary Embolism: While typically presenting acutely, a chronic cough could be a symptom of a chronic pulmonary embolism, especially if accompanied by dyspnea or chest pain.

Cystic Fibrosis: More commonly diagnosed in childhood, but can present in adults with a chronic cough, recurrent lung infections, and malabsorption.
Sarcoidosis: An autoimmune disease that can cause a cough, along with other symptoms like shortness of breath, chest pain, and skin or eye symptoms.
Eosinophilic Pneumonia: A rare condition characterized by a cough, fever, and shortness of breath, often related to an allergic reaction or certain medications.
Bronchiectasis: A condition where parts of the airways are damaged, leading to a chronic cough with sputum production, often accompanied by recurrent infections.