Sword swallowing is risky. That much should be obvious. But people manage to make a career out of putting blades down their throats, so, at some level of skill, swallowing a sword becomes calculated risk. A 2006 study in the British Medical Journal looked at exactly what dangers sword swallowers face—what the complications of sword swallowing might be and how to prevent them.

Radiologist Brian Witcombe consulted 110 sword swallowers from 16 different countries, to get a sense for what the dangers and complications of the trade might be. It’s worth reading the entire abstract:

Major complications are more likely when the swallower is distracted or swallows multiple or unusual swords or when previous injury is present. Perforations mainly involve the oesophagus and usually have a good prognosis. Sore throats are common, particularly while the skill is being learnt or when performances are too frequent. Major gastrointestinal bleeding sometimes occurs, and occasional chest pains tend to be treated without medical advice. Sword swallowers without healthcare coverage expose themselves to financial as well as physical risk.

Finding sword swallowers wasn’t the hard part. They have an association, the Sword Swallowers’ Association International. Their membership requirements are as follows:

In order to become officially recognized and endorsed as an official sword swallower member of SSAI, a candidate must be at least 18 years of age and prove him/herself able to swallow a solid steel sword blade at least 16 inches in length and at least 1/2 inch in width under the following requirements: Swords: Each sword must be available for inspection by officials and witnesses Blades: Each sword must be non-retractable with non-collapsible solid steel blade Length: Each blade must be at least 16 inches (38 cm) in length Width: Each blade must be at least 1/2 inch (2 cm) wide in width

Through surveying these members, the researchers were able to document a few common side effects, like sore throats (which they adorably call “sword throats”) and pain in the chest and lungs. Six of the sword swallowers suffered tears of their pharynx of oesophagus and three of those swallowers had to have surgery on their necks. While nobody in the association has died, three of the survey takers reported medical bills totaling in the range of $23,000 to $70,000. But most sword swallowers don’t go to the doctor when they feel pain, according to the research.

The most dangerous times for a sword swallower tend to be when they’re distracted or swallowing a new or oddly shaped object. And while most sword swallowers didn’t suffer major injuries, the doctors still don’t recommend you pick up the hobby:

Our 46 respondents collectively had swallowed over 2000 swords in the three months before we contacted them but the complications relate to their professional lifetimes. Although the risk of sustaining life threatening injury is low for an experienced swallower while relaxed and concentrating on swallowing a single sword, the risk over a career is high.

Probably better to take up knitting—or juggling, if you’re dead set on joining the circus.