Why are we asking this now?

The boxing world is agog with excitement over the biggest fight involving a British boxer in many years – a world title bout between the Mancunian folk hero Ricky Hatton and an American called Floyd Mayweather that's taking place in Las Vegas in the early hours of Sunday morning UK time. To fans, the WBC world welterweight contest is a classic in the making.

The gifted Mayweather, aged 30, is regarded as pound-for-pound the best boxer in the world. Hatton, a year younger, is a ferocious hitter with the heart of a lion whose appeal derives from his loyalty to his working-class roots. It all adds up to a return to the glory days of boxing – a pure contest of strength, courage and skill between two great fighters, erasing memories of the tawdriness of the Mike Tyson era of the 1980s and 1990s.

Is Mayweather vs Hatton expected to be particularly brutal?

No more than most world title fights, but a huge amount of hype surrounds the contest. Both men are undefeated and the cauldron atmosphere of Las Vegas will only serve to increase the stakes. It's a showdown as big as any in the illustrious history of world title bouts between British and American boxers. The effect has been to lift the fight beyond the sports pages into the general consciousness, and the safety and morality of boxing are once again coming under scrutiny.

Who thinks boxing should be banned?

The British Medical Association has campaigned against boxing since 1982. It reasserted its opposition to all forms of pugilism last September with the advent of Ultimate Fighting contests in Britain, the no-holds-barred form of the sport which has the potential to inflict even greater injury.

The BMA says boxing causes death, brain damage, acute brain haemorrhage and eye, ear and nose damage, including permanent loss of sight and hearing. Although it has called for a complete ban on boxing, professional and amateur, as a first step it says boxing should be banned for children and is campaigning to outlaw it in under-16s.

Paul Flynn, the veteran Labour MP, tried and failed to get boxing banned with private member's bills in 1998 and 2005. As a former boxer himself, Mr Flynn acknowledged that boxing has a glorious past but argued it had become an ignoble art and a "degrading spectacle of gratuitous violence that exploits the least advantaged people".

What kind of injuries does boxing cause?

Knocking a person unconscious can cause permanent brain damage. When Chris Eubank knocked out Michael Watson in their notorious fight at Earl's Court in 1991, it ended Watson's career and very nearly cost him his life. He was in a coma for 40 days, had six brain operations to remove a blood clot and was left wheelchair-bound. Eubank was so upset by what he had done he nearly gave up boxing. Even Watson fared better than Johnny Owen, the diminutive Welsh bantamweight known as "Matchstick Man", who died at the age of 24 after being knocked out in a world title fight against the Mexican Lupe Pintor in 1980 in Los Angeles.

The BMA's 25-year campaign against boxing is based on medical evidence that suggests the sport also causes chronic brain damage, sustained cumulatively over a career rather than in a single bout. The American Medical Association says this affects three out of four boxers who have more than 20 professional fights. The most disturbing case is that of Muhammad Ali, the all-time "Greatest" renowned for his quickness outside the ring as much as inside it. By the age of 45, Parkinson's Disease had reduced him to a shuffling shadow of his former self.

How does the brain react when the head is struck?

The brain is like a blancmange inside a wooden box. It has the consistency of set custard and is secured within a pool of fluid in the skull by veins no more substantial than those on the back of your hand. The arrangement works well until the box is hit. Then the skull suffers rapid "rotation/acceleration/deceleration" – the jerking motion in which the head rocks rapidly back and forth.

The most frequent cause of damage is a torn vein in the skull which bleeds causing a blood clot. This increases the pressure inside the skull, squeezing the brain. Cumulative brain injuries, in which the brain is scarred by repeated blows, are also common over a long career, leading to conditions including the "punch drunk" syndrome, a symptom of which is slurred speech.

Is boxing the most dangerous sport?

Not in terms of deaths. On that measure, horse racing, sky diving, mountaineering and scuba diving are more dangerous. An assessment of their relative fatality rates conducted more than 20 years ago concluded that boxing caused 1.3 deaths per 100,000 participants compared with 11 for scuba diving, 51 for mountaineering and more than 120 for sky diving and horse racing. But the BMA says it is not death but the chronic brain damage that is most worrying about boxing.

Why is the BMAnot calling for other sports to be banned?

Lots of people are injured as well as killed while participating in other sports. The majority view, however, is that if people want to take part in dangerous activities that is a matter for them in which the state should not interfere. The BMA argues that boxing is different because it is the only sport in which the purpose is to cause harm. In other sports, harm is an accidental side effect.

What has been done to make boxing safer?

Two key changes have been made in the past 20 years. Title fights have been reduced from 15 rounds to a maximum of 12 rounds and the medical care at the ringside has been stepped up. At professional fights, a doctor is now on duty and an ambulance stands by to take any injured boxer direct to the nearest neurosurgical unit. If a fighter suffers a brain injury, a speedy operation to remove the blood clot gives him the best chance of recovery.

Why not introduce head guards or ban blows to the head?

These would undoubtedly reduce the risks – and head guards are now mandatory in amateur boxing (including Olympic contests). But they would also reduce the appeal of the sport. Boxing fans are drawn to major bouts for their naked display of aggression and by the prospect of a knockout – something that is very difficult to deliver with a blow to the body. Stricter rules or protective gear might save boxers' lives, but they would kill the sport.

Should boxing be banned?

Yes...

* It is the only sport in which the objective is to cause harm to your opponent

* It carries a major risk of brain damage, with three out of four professional boxers affected

* It has no place in a civilised society, encourages gratuitous violence, and is already banned in some countries

No...

* There are many sports, including mountaineering and sky diving, that are more dangerous than boxing

* Individuals should be free to make their own choices about what risks they take

* The sport has a huge following, an international television audience and sustains thousands of jobs