When a patient presents with nasal obstruction a correct diagnosis must be made. Treatment may not always be required, and the need for intervention should be balanced against the risks of therapy. If the patient has an acute problem, such as the common cold or sinusitis, a topical decongestant may be the most immediately effective remedy, but this should never be continued for more than a few days and the patient should be warned against buying similar proprietary products. In more chronic cases, such as allergic or vasomotor rhinitis, or when decongestion of mucosa away from the nose (Eustachian tube) is required, oral treatment is best. A sympathomimetic administered orally (pseudoephedrine or phenylephrine) may be sufficient, or an antihistamine alone may be helpful in allergic rhinitis. Combination products are frequently effective, possibly more so than the individual ingredients, but when using such products the prescriber must remember the contraindications and precautions for each ingredient.