It’s no secret that American children and teens occasionally push the envelope of safe behavior, but today’s teens are pushing a different kind of envelope — daring each other to take risks that are not just dangerous but potentially deadly. From choking themselves to taking random pills to swallowing cinnamon, these so-called “games” may result in asphyxiation, chemical overdose, brain injury and even death.

The Centers for Disease Control and Prevention (CDC) tracks injury and death rates for some of these activities, but the statistics are difficult to pin down. For example, death certificates don’t distinguish between someone who died from playing a choking game and someone who died from another form of asphyxiation.

Barbara Greenberg, PhD, a clinical psychologist in Connecticut who specializes in treating adolescents and their parents, has counseled teenagers who have risked their lives with these activities.

Peer pressure plays a big part. “Teens will do in a group what they wouldn’t ordinarily do,” said Greenberg. “Teens in general tend to behave more sexually and aggressively in a group. It’s not that teens aren’t aware of risks — it’s that they weigh the benefits of the excitement more heavily than they weigh the risk.”

Parents are often oblivious to the games their kids play, but it pays to look for warning signs. Depending on the activity these may include bloodshot eyes, suspicious marks on a neck, personality changes, frequent headaches, loss of concentration, disorientation after spending time alone or unusual questions about the effects of strangulation, according to the CDC.

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Here are 12 dangerous games your child may play:

1. Choking game. This game involves strangulation by using a noose or strap to cut off the oxygen supply to the brain and create a high. A CDC study into 82 reported choking game deaths found those who died ranged in age from 6 to 19, with the average age being 13 years old. Almost all of those who died were playing alone. Most of the parents (93 percent) were unaware that the game existed, according to the CDC.

2. Cinnamon challenge. This game made headlines after being seen on YouTube and was the subject of a segment on “‘Mythbusters,” a Discovery Channel series that uses science to test popular myths and rumors. Someone swallows a teaspoon full of cinnamon, which immediately dries out the mouth. The painful effects may include violent coughing and vomiting. The cinnamon can also enter the lungs and require respirator-breathing support.

3. Knockout challenge. This is another asphyxiation game. A teen inhales and exhales rapidly, causing hyperventilation. Another youth then presses against his or her chest to inhibit air flow, causing the child to lose consciousness.

4. Car surfing. A teen surfs on top of a moving car’s hood, roof or trunk. According to the CDC, nearly 100 teens have died from this game in the past 18 years.

5. Chubby bunny. Players put as many marshmallows in their mouth as they can and try to utter the words “chubby bunny.” Some have choked while playing.

6. 30-second fight game. Kids brawl violently for 30 seconds, causing potentially serious injuries. Onlookers watch the fight and declare a winner at the end.

7. ABC games. Using a fingernail, something sharp or even a pencil eraser (this is known as the eraser game), one person digs at another youth’s skin while they list words beginning with each letter of the alphabet. The skin breaks but the game continues until the child either gives up or finishes the alphabet game.

8. Sack-tapping. Similar to an old game involving punching someone in the arm until they give up, this game targets the testicles. It has led to permanent injuries, in some cases requiring surgical removal of one or both testicles.

9. Robotripping. A kid chugs a full bottle of cough syrup. The syrup produces a high induced from the chemical DXM (dextromethorphan), which in large doses can produce hallucinations and can kill in excessive amounts. More than one in 10 teens has used over-the-counter cough or cold medicines to get high, according to the Drug Enforcement Agency.

10. Gallon challenge. In this game, a child drinks a gallon of water or milk within a one-hour period. The human stomach can’t handle this volume, so the person becomes violently ill, vomits and may suffer diarrhea and cramps.

11. Ice and salt challenge. In this game, the skin is moistened, salt is added and then ice is applied. This causes severe pain until the player gives up. The result can include severe skin damage from frostbite.

12. Skittling. This life-threatening game consists of grabbing pills from the medicine cabinet, mixing them up and swallowing a small and random handful of them.

Parents need to discuss these games with their children and the dangers they pose, Greenberg advises. She suggests parents research these activities, look on video sites like YouTube and show their children some of these videos so they can discuss the games them. Most important, parents need to keep the communication channels open with their kids.

“The more communication kids have with their parents, the less influence they feel from peer pressure — and the less likely they are to take risks,” Greenberg says.

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Ronald Agrella is a freelance writer and former editor of The Boston Globe’s