Could you imagine not being able to smell bacon frying, or freshly cut grass, or the presence of smoke?

People who lose their sense of smell face difficulties that can affect their daily lives and put their health and safety at risk, a new British study suggests.

It included 71 patients, ages 31 to 80, who lost their sense of smell. They reported a number of problems — from concerns about personal hygiene to loss of sexual intimacy and the breakdown of personal relationships. They also reported physical health consequences and the difficulties and cost of seeking help.

"Smell disorders affect around 5% of the population and cause people to lose their sense of smell, or change the way they perceive odors. Some people perceive smells that aren't there at all," said researcher Dr. Carl Philpott, a professor of rhinology and olfactology at the University of East Anglia's Norwich Medical School in England.

There are many causes, he said, including infections, injury and neurological diseases such as Alzheimer's. Some medications also cause a loss of smell.

Previous research has shown that people who can't smell also report high rates of depression, anxiety, isolation and relationship issues, Philpott said.

"One really big problem was around hazard perception — not being able to smell food that had gone off, or not being able to smell gas or smoke. This had resulted in serious near misses for some," he said in a university news release.

But smell isn't just a lifesaving sense — it is also life-enhancing, Philpott added.

"A large number of the participants no longer enjoyed eating, and some had lost appetite and weight," he said. "Others were eating more food with low nutritional value that was high in fat, salt and sugar — and had consequently gained weight."

Social lives were also greatly affected by a lack of smell. "We found that personal hygiene was a big cause for anxiety and embarrassment, because the participants couldn't smell themselves," Philpott said. This could affect sexual and personal relationships.

The researchers said they hope their study will help persuade doctors to take loss of smell more seriously, and provide better help and support to patients.

The findings were recently published in the journal Clinical Otolaryngology.