Have you ever wondered why there are no 13th floors in hotel or apartment buildings? No 13th rows on airplanes or a 13th gate? Why there is no 13th deck on a cruise ship?

It is because there are people in the world who suffer from the condition called “triskaidekaphobia.” It is the irrational and morbid fear and avoidance of anything having to do with the number 13.

Some say it is based on superstitions consolidated over the years with events associated with the number 13, and is commonly linked to the early Christians, since the number 13 is mentioned several times in the Bible. For example, there were 13 people present at the Last Supper and the 13th individual ended up betraying Christ. To this day, it is considered unlucky to have 13 people at a meal, in the belief that someone at that table will die within the year.

Other historians link the avoidance of the number 13 to Norse mythology. The story goes that when the 12 primary gods were dining at a table, the 13th god, Loki, the god of mischief, descended on the group and wreaked havoc and carnage.

In addition to the fear of anything having to do with the number 13, there is also a condition called “paraskevidekatriaphobia” or it is sometimes called “friggatriskadekaphobia” — or simply fear of Friday the 13th. There are two of these dates in 2023 — the next and last one is Friday, Oct. 13.

Even if you don’t have a fear of Friday the 13th, in an article from Reader’s Digest, written by Meghan Jones, approximately 10% of Americans are at least a little uneasy about the day.

Yet in some cultures the number 13 is considered lucky; Italy and some Cantonese-speaking regions, for example. The website www.mathworld.wolfram.com suggests it is the most widespread superstition in the United States, possibly affecting millions of people.

These disorders can severely affect a person’s life. For example, if a person realizes there are 13 things in their refrigerator, they will throw out one to bring the number to 12 or buy additional items to increase the number beyond 13. Or, if they find they have 13 shirts, they will throw one away to make 12, or go out and buy more shirts so they have more than 13.

Symptoms from exposure to anything related to 13 include anxiety, worrying obsessively, sweating and heart palpitations. There is no known cause for triskaidekaphobia, but there are treatments including therapy and medication.

There have been several famous people who have suffered or suffer from triskaidekaphobia. These individuals, cited on www.phobia.fandom.com, include former United States Presidents Herbert Hoover and Franklin D. Roosevelt and writers Mark Twain and Stephen King.

Not to be left out, Hollywood capitalized on people’s fear of Friday the 13th by making movie after movie, creating a franchise, about a serial killer who supposedly kills his victims on Friday the 13th.

But remember — there are no lucky or unlucky numbers. They are all just numbers.