What is it that wrestlers, boxers, rugby players and MMA fighters have in common? Strength? Toughness? Courage? Fitness? No doubt. But to your average person, the most visible answer is none of these. It's the ears. Some fighters regard their cauliflower ears as trophies to be proud of, some see them as an annoyance but to most of us they're just part of the sport.

The ear-or auricle - has two main functions. It protects the ear canal from damage, and it has a special shape that allows it to act as a funnel to channel sound waves. It consists of soft cartilage covered with skin. This arrangement allows the ear the flexibility to bend, fold or twist so that you can pull your head out of small spaces, and the ear will spring back to its original shape.

The initial stage of a cauliflower ear (known in medical terms as an auricular haematoma) is most often caused by impact to the ear. It may also result from vigorous twisting or friction, such as when trying to pull the head out of a headlock or triangle.

The cartilage itself is surrounded by a lining called the perichondrium. Trauma to the ear can cause damage to the small blood vessels between the perichondrium and the cartilage, and blood leaks into the area creating swelling. The ear may be very sore and painful to touch.

It is generally quite obvious when this happens. Some people worry that a cauliflower ear will gradually build up over time like a callous, and I remember in my early days of training checking anxiously in the mirror to see whether mine had started growing yet. It doesn't happen that way - if your ear is going "cauli", then you'll almost certainly know about it. If nothing is done at this early stage, then fibrous scar tissue is produced and begins to replace the fluid, building up into a hard lump. It is this (and not the blood 'going hard') which gives the ear its characteristic 'cauliflower' look. Once this has happened the result is permanant.

Many fighters don't mind having a cauliflower ear, and some even welcome it. Others don't relish the prospect, but can't be bothered to go to the trouble of avoiding it. Think carefully, though, because once you've got one, it's with you for life and it can affect your hearing as well as limiting your choice of headphones. Ears are the shape they are for a reason.

What is the best way of avoiding a deformed ear? As always, prevention is better than cure. Wearing wrestling ear protection, consistently, is a reliable way of keeping your ears beautiful. The problem is that few fighters keep this up for long. Most only wear ear protection while they have problems, and once the initial pain goes away the earguards sit growing mould at the bottom of the training bag.

So, you've been walloped round the side of the head and your ear is really sore, a bit squidgy and starting to swell. What now? As soon as possible, try to apply some ice. This can be used for a couple of minutes on, followed by a couple of minutes off, and then repeated as often as necessary. If you catch it soon enough, before the swelling has really got going, then this-together with a couple of days of compression (described below)-might just do the trick. If it doesn't, read on.

Should you find yourself with a sore ear that has ballooned up to what seems like golf ball proportions, what is the best course of action? Even at this stage, it is often possible to avoid a permanent cauli, if it is treated correctly. There are two things you need to do, and speed is of the essence - you need to act within a few days.

The first thing is to get the ear drained. My advice is to go to a doctor or walk-in clinic to get this done safely. The reception you will get depends very much on the doctor. Some are sympathetic, others less so.

Many fighters, for convenience or because they feel they can do the job better themselves, choose to drain their own ears. I don't recommend this. For those considering it as an option, I will mention two caveats. Firstly, remember the danger of infection: everything used must be sterile, and the ear surface itself disinfected. Secondly, if you drain someone else's ear for them then you could potentially find yourself in a very dicey legal position.

After the ear has been drained, the second thing is to compress it properly. There are a number of ways to do this; one method is to apply antiseptic cream, then pack the ear with slightly damp cotton wool. Add some more cotton wool behind the ear, so that it sits at a natural angle (many people leave out this step, but it makes the compression a lot more effective, and helps keep the shape of the ear better). Tape the whole arrangement firmly to the head. This needs to remain in place for at least a couple of days, otherwise there is a good chance that the haematoma will recur.

Why is it, then, that some fighters have perfect ears, even after years of training and competition, while others only have to look at a wrestling mat for their ears to start swelling? The answer is that it's mostly down to genetics. Some people are, for some reason, more prone to cauliflower ears. As with other injuries, the risk probably increases as you get older.

I once heard a judo coach insist that the way to prevent cauliflower ears was to warm them up by rubbing them vigorously before a training session. This increases the blood flow and allegedly reduces the risk of damage. I'm not entirely convinced, but I've not been able to find any evidence one way or the other.