Medical Briefing

Recently, a young man came in to renew his third-class medical certificate. In the waiting room he appeared somewhat nervous, and when I read my nurse's first blood pressure reading, I found out just how nervous he was. His pulse was rapid, and his blood pressure was elevated. When I entered the room, I chatted with him casually. "What kind of plane do you fly?" I asked.

"A Cessna 172," he answered. Then his eyes brightened and he asked, "Are you a pilot, too?" I said I was, and he asked how long I had been flying. After glancing at his birth date on the medical certificate application, sheepishly I said I'd earned my certificate three years before he was born. He laughed and relaxed.

Then I took his blood pressure. It was quite normal, and his pulse had slowed to 72.

What this young man displayed is called "white coat hypertension." It's a condition where people, particularly aviators, become anxious during a medical exam. Given the importance of a medical certificate to a pilot, this condition is normal, and so is the body's reaction to it.

Anxiety releases adrenaline, and adrenaline increases our pulse rate as well as our blood pressure. The result is a blood pressure reading far above normal. Aviation medical examiners (AMEs) who are pilots (as many of them are) understand this well. When I teach a class of new AMEs, I always remind the non-pilots about how stressful a flight physical is for every pilot. "How would you like to take a periodic test, and if you fail, they take away your license to practice medicine? That is the kind of pressure pilots are under when they see us."

In late 1996 the FAA changed its blood pressure standards for pilots. Previously, very high blood pressure levels, such as 160/95 (millimeters of mercury, or mmHg), were "acceptable" for pilots holding third-class medical certificates. This was not good medical practice, but it had not been changed since the 1950s. The new standards say that rather than having to meet specific blood pressure values to pass a flight physical, pilots merely need to be "well controlled."

Many things in medicine have changed, of course. In the 1960s, the U.S. Air Force began allowing its pilots to be treated for high blood pressure using a certain, specific drug. By the late 1970s, the Air Force used three different drugs to control blood pressure in its pilots. It wasn't until the early 1980s that the FAA routinely followed suit. Now, the FAA not only permits, but encourages this practice. So long as there are no adverse affects from the treatment, the FAA will permit an aviator whose blood pressure is controlled to hold any class of medical certificate.

What is blood pressure? When a heart beats, it squeezes blood into the arteries. The arteries are not steel pipes, but rather, tubes of muscle. They relax and allow the blood to flow through them when pressure goes up. In between heart beats the pressure begins to drop off, so the arteries contract to help maintain the pressure.

The maximum pressure reached is called the "systolic" and the minimum is "diastolic." These pressures are measured dynamically in the series of sinusoidal pressure waves your heart generates as it beats. Generally, a systolic of anywhere from 100 to 140 mmHg and a diastolic of 60 to 90 mmHg is normal.

If the arteries become stiff - a condition called atherosclerosis or hardening of the arteries - they lose the ability to contract and maintain an average pressure. Because the arteries are now starting to act like rigid, steel pipes, the systolic tends to climb, sometimes to 180 mmHg or more, while diastolic may fall. Eventually, they both rise.

The effects of rising blood pressure begin to damage almost every organ in the body, which speeds the hardening of the arteries. The kidneys are damaged. Blood vessels may begin to bulge and finally rupture. A blood clot forms and may block the vessels, or the clot may break through the vessel's wall and allow bleeding into the tissues, as in a stroke. All these are catastrophes, and a pilot certainly wants to avoid them.

Controlling your blood pressure is important. When you're young, it's relatively easy to do. First, don't smoke. One major airline used to forbid hiring smokers. As a result, pilots on that airline today have less than half the heart attacks and other related problems of any other airline. More than 98 percent of its pilots reach mandatory age-60 retirement with their medical certificates intact.

Avoiding use of tobacco is the single most important thing you can do to avoid having high blood pressure later in life. Don't start smoking, and if you have started - stop.

From the standpoint of prevention, you should exercise three to five times a week for at least 30 minutes. Exercise is vigorous and produces sweat. Golf is not exercise. Brisk walking is just as good as jogging, bicycling, or swimming. Interval exercise like tennis and racketball is good too, but you must double the time for the aerobic benefit.

Other important things you can do to maintain a healthy blood pressure are control your weight and avoid eating too much fat. Avoiding salt is important only if you have a family history of sensitivity to it.

Also avoid alcohol in excess. What is excess alcohol? From a medical standpoint, any drink within 12 hours of flying is excessive, and preferably none within 24 hours. Beyond that, refrain from having more than two drinks on a daily average.

Some studies have advocated red wine as a prevention for heart disease. There is a protective chemical in red wine, but it's also in grape juice. If you already drink a glass of wine a day, that's okay, but don't start drinking simply for the health benefits. Have juice instead. However, don't believe claims of a single magic food or vitamin that will do everything for you. You'll just rush from one fad to another. Simply eat a balanced diet with plenty of fruits and vegetables.

It's far easier to prevent high blood pressure than it is to treat it, but if need be, control your blood pressure. If you're a person who always has white coat hypertension, buy yourself an automated blood pressure machine. They cost $30 to $50. Then train yourself by taking your own blood pressure twice a day in the weeks before you go in for your examination. You'll feel a lot more relaxed when the nurse slips that blood pressure cuff around your arm.