A cough that persists daily for a year may be due to allergies, asthma, sinus drainage, acid reflux, smoking, chronic bronchitis, postnasal drip, environmental irritants, or long-term lung conditions. Some blood pressure medicines can also trigger a persistent dry cough in certain people. If the cough has not improved despite multiple treatments, the underlying cause may not have been fully identified yet. Doctors may sometimes recommend a chest X-ray, CT scan, lung function tests, allergy evaluation, sputum testing, or acid reflux assessment, depending on symptoms such as wheezing, mucus, throat irritation, breathlessness, or weight loss. Treatment usually works better when focused on the exact cause rather than repeatedly changing cough syrups or antibiotics. Steam inhalation, avoiding smoke exposure, staying hydrated, and reducing dust exposure may also help reduce irritation. Blood in sputum, chest pain, unexplained weight loss, fever, night sweats, or increasing breathlessness can indicate a more serious lung problem and may need deeper chest evaluation for appropriate treatment planning.