Dear Doctor K: I have a teenage son who plays high school football, so I’m interested in the new concussion guidelines. Can you tell me what they say?

Dear Reader: In March of this year, the American Academy of Neurology released new guidelines for recognizing and managing sport-related concussions.

These guidelines could help protect the brains of athletes at all levels of play, from professional football to youth soccer. In a phrase, the new concussion guidelines recommend “when in doubt, sit it out.”

Concussions occur when something makes the head and brain move quickly back and forth. This can be a jolt to the head, a fall or a blow to the body. They cause a short-term disturbance in brain function. Contact sports such as football and ice hockey are most likely to increase the risk of concussions, but concussions can happen in any sport.

Many athletes don’t get medical attention for concussion. That’s often because they or their coaches don’t recognize the warning signs or take them seriously. Concussions can cause temporary loss of consciousness. They also typically cause confusion and problems with recent memory. The confusion may occur immediately, or a few minutes after the injury.

Other symptoms of a concussion often include dizziness, nausea (with or without vomiting) and headache. After a concussion, a person may seem to have trouble paying attention to you, or may seem to be lost in his thoughts. His speech may be slow or even slurred. A few days later, the person who has suffered a concussion may seem moody or depressed, may be bothered by amounts of light or noise that never used to bother him, and may have poor quality sleep.

All these symptoms can be pretty subtle, and if they occur during an exciting sporting event, the people who are evaluating the person may be distracted. In other words, it can be hard to determine if a person has really suffered a concussion.

The new guidelines take the guesswork out of the equation. They step away from having coaches or trainers try to diagnose concussions on the field or sidelines. Instead, they recommend that athletes who are suspected of having a concussion should be immediately removed from play and evaluated. What’s more, the guidelines state that athletes who have sustained concussions should not return to play until a licensed health care provider gives the green light.

Not all concussions are serious. Many young people and athletes recover from a head injury in minutes or hours. The danger is that athletes who have had one concussion are at greater risk of having another. The first 10 days after a concussion is a period of special danger. Repeated minor head injuries over a short period greatly increase the risk of serious or permanent brain damage.

The next step is to educate coaches and trainers about the new guidelines.

They are the people who have ringside seats when concussions happen, and they’re making the decisions about whether to let the athletes continue to play.