DEAR DR. DONOHUE: I am concerned about serious or long-lasting injuries associated with wrestling. My middle-school grandson mentioned blurry vision for a few moments after hitting his head on the mat in a takedown move. He also had a very sore neck as a result of a hold with his opponent’s weight pressing on him. I’d be interested in your comments on the safety of this sport. — S.W.

 ANSWER: No sport is free of injury. When ranked in order of injuries to the entire population, including school athletics, biking and fishing account for more head injuries than wrestling. In high-school sports, football, hockey and baseball are responsible for more serious injuries.

 Wrestling is an excellent sport. It combines strength training, aerobic conditioning (heart exercise), anaerobic conditioning (speed exercise), balance, flexibility and reaction time in one sport. Those are qualities that will serve your grandson well throughout his life.

 Your grandson’s head injury qualifies as a mild concussion. Unconsciousness is not essential for the diagnosis of concussion. Disorientation, incoherent speech, memory deficits, the inability to retain new information, visual phenomena, clumsiness, transient headache — any or all of these qualifies as a concussion. Your grandson’s would be called a mild traumatic brain injury, one that isn’t going to cause permanent damage. You might have seen the deluge of information that has been printed recently about concussions in professional football players and how they have led to early onset dementia. Everyone is looking for ways to prevent such brain injuries. Youngsters’ brains are slower to heal than are adults’, so they require even greater caution. When to return a boy or girl to active participation is a judgment that should be made on the conservative side.

 Parents and grandparents have to depend on the training of the school’s coaches and ancillary medical personnel to be fully aware of the potential dangers of even mild head injuries.

 I believe your grandson’s neck injury is a muscle strain. It should be gone in a week or two at the most.

 DEAR DR. DONOHUE: I am 81 years old, in good health, have regular check-ups, am 5 feet 5 inches tall and weigh 135 pounds.

 I recently picked up a pedometer and would like to know what you consider acceptable as to the number of steps per day for a person of my age. — A.B.

 ANSWER: You made a good investment. A pedometer is a good measure of daily exercise, and it gives you a goal. At older ages, everyone should first check with the doctor before launching into an exercise program.

 For a few days or a whole week, wear the pedometer, but don’t change anything you do. You’ll find out the average number of steps you take in a day. Add 200 more steps to that total, and that would be the number of steps to aim for every day.

 You can add more steps gradually each week until your total is 1,000 to 2,000 steps a day. And you can divide your daily walks into three sessions if you wish.

 At younger ages, we’re told to get in 10,000 total steps a day, a distance of 5 miles. No one has to start at that level. Beginners should settle for a more modest number.

 DEAR DR. DONOHUE: I do senior-type exercise regularly — calisthenics for an hour three times a week

 My heart rate increases only one to three beats a minute. I take nadolol (Corgard) for high blood pressure and control of my heartbeat. Am I getting any benefit from the exercise? — W.S.

 ANSWER: Nadolol is a beta blocker, a medicine that slows the heartbeat. It makes it impossible for you to use heartbeat as a criterion for the benefit of exercise.

 You can use “perceived exertion” to judge the strenuousness of exercise. Do you feel that the exercise is taxing you? If you can say yes, then you’re benefiting from your exercise.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475. Readers may also order health newsletters from www.rbmamall.com.