6 common causes for smell and taste decline

We rely on our smell and taste senses to help us enjoy the finer things in life, but we often take them for granted. Here are six culprits for their decline.

• We all know that colds, flu and other respiratory infections may temporarily affect our senses of smell and taste.
• And sometimes smell receptors in the nose are damaged and sense loss persists, possibly because viruses interfere with receptor cell replacement.
• About 20 per cent of smell and taste disorders are due to viral infections, and are most likely to occur in middle age, with women affected more often than men.
• Most people have only a partial loss of smell, which may be accompanied by smell distortions.

• People who suffer from chronic infections and inflammation of the middle ear may also experience a blunting of their sense of taste.
• As both hearing and taste could be affected, it is well worth ensuring that you get appropriate treatment for any ear infections. 

• There are several forms of rhinitis, a medical term meaning that the membranes lining the nose are irritated and inflamed.
• Smell receptors are either blocked off or insensitive. It is most often due to allergies, such as hay fever, causing cold-like symptoms of a blocked, runny nose, sneezing, and itchy eyes. Other causes include infections or pollutants and irritants such as cigarette smoke.
• There are numerous treatments that may alleviate some or all symptoms, so go and see your doctor or, if the problem is severe, ask for a referral to an allergist.  

• Inflammation of the mucosal lining of the sinus cavities — small air-filled spaces within the bones surrounding the nose — is usually due to infection, such as a cold, and generally clears up within a few weeks.
• But sometimes sinusitus, following an acute infection, can last for three months or more, especially if the person also smokes or has allergic rhinitis, nasal polyps, asthma or impaired immunity (as a result of AIDS, for example, or during chemotherapy).
• It may also occur with infection spreading from an infected tooth. The mucous lining of the sinus can become damaged, mucus builds up and drainage channels may be blocked.
• Loss of smell sensation often results, but various treatments, including medication and surgery, can be effective.  

• Nasal polyps are growths within the nasal passages that can cause loss of smell by blocking the nasal air passage, so that odour molecules in the air cannot reach the smell receptors at the top of the nose.
• Sometimes loss of smell is the first clue to polyps; as they are readily treatable, it's worth asking your doctor if this could be the problem.   

• Many medicines, both prescription and over-the-counter, can interfere with the sense of smell. These include antibiotics, antihistamines, amphetamines, the contraceptive pill and the anti-impotence drugs ildenifil (Viagra).
• Prolonged use of nasal decongestant sprays can also damage the nasal lining and lead to smell disorders.