Whether they're caused by an infection or an allergy, nasal conditions such as rhinitis, nasal congestion, sinusitis and post-nasal drip are some of the most common complaints seen in pharmacy.

Many of these conditions tend to have some degree of overlap, so it can be difficult to distinguish between them. For instance, it's possible for someone with rhinitis to also report nasal congestion, or someone with a stuffy nose to also suffer from sinus pain. It's therefore important to ask customers to describe their symptoms carefully as this will help you to offer effective treatment and advice.

Rhinitis is the medical term for inflammation and swelling of the mucus membrane inside the nose. This inflammation increases the amount of mucus produced and, as a result, customers may complain of a runny nose, sneezing, nasal congestion and a feeling of mucus dripping or trickling down the back of their throat.

Rhinitis can be defined by the duration of symptoms - acute (short-lived) or chronic (longer-lasting). Here, we focus on acute rhinitis:

Acute allergic rhinitis

Allergic rhinitis is triggered by an allergic reaction to an allergen such as pollen, pet dander or house dust mites.

Acute non-allergic rhinitis

Non-allergic rhinitis can be caused by:

• A viral infection - e.g. the commoncold
• Environmental factors - e.g. a dry atmosphere, smoke, a change in temperature
• Hormonal imbalance - e.g. during pregnancy, puberty or when taking oral contraceptives or hormone replacement therapy
• Rebound congestion - the medical name for this is 'rhinitis medicamentosa' and it is caused by the overuse of nasal decongestants. You may have heard it referred to as rebound congestion. Anyone with repeated symptoms of congestion following use of a nasal decongestant, should be referred to the pharmacist.