A cough lasting 2 days is usually due to a common cold or a mild viral infection and typically resolves on its own. Since your cough comes and goes, it may also be triggered by environmental irritants such as dust or smoke or by a mild allergic reaction. You should rest, stay well hydrated, and drink warm fluids such as tea or soup. You may also try honey to soothe the throat while avoiding irritants. Consult your doctor if the cough lasts more than two weeks or if you develop chest pain or worsening symptoms.