Vocabulary: human senses 词汇：人的感觉

A trained sniffer dog can find hidden drugs or earthquake survivors and even detect cancer. We might not have as good a sense of smell as dogs, but we still follow our noses. Wake up and smell the coffee! Something smells fishy. She has a nose for a bargain. The English language is full of idioms to do with smell, and many of them show how important smell is to our sense of judgement.

And that's not surprising, because a sense of smell is very useful in telling when food is off, or clothes need washing, for example. But millions of people can't smell anything at all: to use a medical term, they are 'anosmic.' In the UK alone, around 3 million people are anosmic, but the country's first clinic to help them has only recently been set up.

So how do people lose their sense of smell? Some people are born that way, they are congenitally anosmic. Others lose their sense of smell because of a head injury, or illness. Those with congenital anosmia might not know what they're missing, but people who lose their sense of smell often become depressed.

It's not only scents which are missing for people with anosmia. Food and drink lose their appeal too, because smell accounts for around 80% of our sense of flavour. They can't taste herbs, spices or garlic and fruit and wine simply taste sour.

Anosmia can also be dangerous. People with anosmia can get food poisoning, because they can't smell when food is bad. They can't smell smoke from a house fire, or leaking gas. Sarah Page is a patient at the new taste and smell clinic. She once turned the gas cooker on by mistake. Unable to smell it, Sarah was unaware that the house was filling with gas, which could have exploded at any time. It was some time before her mother came home and realised the problem.

Sarah is going to have an operation to treat her condition in the next few months. If it's successful, she says that what she wants most isn't to avoid danger. She would like to share the olfactory world of other people, including the bad smells. Sarah says, "People go 'Oh, that stinks' - I want to be able to understand why that's a bad smell and join in with that conversation."