In many cases the diagnosis of AR will be based on the history and clinical features alone. Many people with the condition never undergo formal testing (e.g. with skin prick testing).

A diagnosis of AR should be suspected if there are the typical clinical features of sneezing, nasal itching, rhinorrhoea and nasal obstruction. Nasal secretions are usually clear; yellow-green secretions occur if the cause is infectious (e.g. viral). Nasal obstruction can be partial or complete and usually affects both sides of the nose. A history of recent exposure to grass pollen, animal dander or house dust mite helps to confirm the diagnosis. A family history of atopy makes the diagnosis of AR even more likely, but a number of non-allergic triggers (e.g. viral infections, drugs, occupational irritants, smoke and air pollution) can induce nasal symptoms that mimic AR. 

Some drugs can make symptoms of AR worse (e.g. alpha-blockers, beta blockers, aspirin, ACE inhibitors, chlorpromazine, aspirin, NSAIDs, oral contraceptives and cocaine). Rebound nasal congestion can occur when stopping prolonged treatment with intranasal decongestants due to rebound vasodilation, which is also known as rhinitis medicamentosa.