Many passengers always seem to set off an airport body scanner every time they go through airport security at the airport.

This can certainly be a frustrating and stressful experience, especially as they are likely to be subject to a pat-down every time they fly.

But why does this always seem to happen?

5 Reasons You Keep on Setting Off Airport Body Scanners

1. You Have a Medical Problem

Airport body scanners are able to detect medical problems because they scan for abnormalities or bulges on passengers through radiofrequency waves.

If you keep on setting off an airport body scanner for no seemingly apparent reason, it would be wise to go to a doctor, and also use a TSA Notification Card.

2. You Are Overweight

Passengers who have a higher body fat content are more likely to set off airport body scanners.

Harmless things like lipomas (fatty lumps) or lipodystrophy (abnormal distribution of fat) could also show up on airport scanners.

3. You Have One of These Hairstyles

False alarms are more likely to be triggered if you have an afro, braid or dreadlocks.

A report found that members of the African American community are therefore more likely to set off airport body scanners, as these hairstyles as more common with this community.

Passengers who wear turbans and wigs are also more likely to set off the scanners.

4. You Have an Implant

90% of artificial joints are able to set off airport metal detectors, even though many implants today are also instructed from ceramic and plastic materials.

Dental implants, on the other hand, are very unlikely to set off a scanner.

5. You Forgot to Remove a Metallic Item

The simplest and most common reason why you might set off an airport body scanner is because you forgot to remove a metallic item, such as your watch, belt, or jewelry.

There are also items that you think wouldn’t set off the scanner but might actually do so, depending on how high the sensitivity of the scanner is set to, such as a headband or underwire bra.

Can You Refuse to Go Through an Airport Body Scanner?

If you keep on setting an airport body scanner, you might be wondering if you can simply refuse to go through the scanner.

While you can refuse to go through the scanner – at least in the U.S. – you will instead be subject to a physical body search instead.

In other countries, such as the UK, you are legally required to go through the scanner otherwise you will not be able to pass through airport security and board your flight.

What Airport Body Scanners See

Airport body scanners are mainly used to detect if a passenger is attempting to fly with a weapon or explosives.

Terahertz Scanner hidden object detection
A Terahertz Scanner showing a hidden object

So, this means that airport scanners cannot see your naked body or inside a body cavity, though can see through clothes.

How Airport Body Scanners Work

Airport body scanners either use backscatter or millimeter wave technology.

Backscatter X-ray scanners reveal if you have any solid items on you by hitting you with harmless ionizing radiation.

Backscatter X-ray image
What a Backscatter X-ray sees

Millimeter-wave scanners show everything you have on you by constructing 3-dimensional animated images by bouncing electromagnetic waves off you.

Ella Dunham, a Freelance Travel Journalist and Marketing Manager, boasts an impressive career spanning eight years in the travel and tourism sectors.

Honored as one of "30 Under 30" by TTG Media (the world’s very first weekly travel trade newspaper), a "Tour Operator Travel Guru" and "Legend Award" winner, Ella is also a Fellow of the Institute of Travel, a Member of the Association of Women Travel Executives, has completed over 250 travel modules, and hosts travel-focused segments on national radio shows where she provides insights on travel regulations and destinations.

Ella has visited over 40 countries (with 10 more planned this year).