Aeromedical Forum

You are always tired. You can’t remember a darn thing. You can’t concentrate. You always feel cold. Therefore you have,

• Lack of sleep

• Job and/or marital stress

• A hideous life-threatening disease

• Low thyroid

Trick question! The answer is any or all of the above. Please be reassured, however that Option C rarely is the case. In contrast, low thyroid or hypothyroidism is a fairly common cause of all those complaints. Problem is, choices A and B are even more common causes of feeling like you’ve been run over by a truck.

Just to confuse things a bit more, back in the old days a lot of docs used to prescribe a small amount of thyroid extract to folks that complained of “the blahs.” Mind you, it did no more than placebo but at least you had a nice chat with your health care provider.

All four of these conditions can degrade your performance as a pilot. Therefore if you have persistent symptoms of this type, it is important to find out why and to get appropriate therapy. We’ve talked about sleep deprivation (Oct., 2013, Sept., 2011) and stress in the cockpit (Aug., 2013, July, 2012, June 2010) as well as a bunch of other health problems that can screw you up for flying.

Low thyroid is another potential “gotcha” for the aviator. It’s a very common problem. It’s present in about 5 percent of the population and in as much as 15 percent of older adults. It is more prevalent among whites and Latinos. It happens when your thyroid gland doesn’t produce enough thyroid hormone.

Thyroid hormone or thyroxin affects many different processes in the body, speeding up metabolism. You might call it the straw boss of the body. When the boss is away, folks start leaning on their shovels. Symptoms include fatigue, lethargy, weight gain, poor appetite, cold intolerance, hoarseness, constipation, weakness, pain in the muscles and joints, tingling and dryness of the skin and hair loss. Depression and limited initiative are common. Not the kind of things you want when you’re shooting a missed approach!

A deficiency of iodine in the diet used to be a common cause of hypothyroidism. It’s pretty rare in the US since they started fortifying table salt with iodine. Here in the States, the thyroid conks out most commonly from an autoimmune process called Hashimoto’s thyroiditis. For some reason the immune system attacks the proteins of the thyroid gradually destroying the gland over a period of several years. It is a gradual insidious process.

That’s why most folks are slow to recognize anything is wrong. A lot of folks say “I guess I’m just getting old and wearing down!” Fortunately it’s pretty easy to diagnose hypothyroidism. A quick and relatively inexpensive bold test should give your doc an accurate picture of thyroid function. Even more fortunately, treatment is simple and effective: thyroid hormone supplement. All you have to do is take a pill called levothyroxine (variously marked as Synthroid, Levoxyl, Levothroid, Unithroid, Tirosint, Levo-T). The catch is you have to take it every day forever. If you don’t your symptoms will slowly recur until you begin to resemble a downed-out bull frog!

Of course the next question is, “What do I do for my medical certificate if I am hypothyroid?” Fortunately since this condition is common and is usually easily correctable, there is a good chance that your AME will be able to issue you a certificate on the spot. Of course there are a few catches.

• First of all you need to bring a report from your treating physician stating that he/she finds your condition stable on your current program and that he recommends no changes.

• Second, you must be free of any symptoms related to low thyroid. This includes fatigue, mental status impairment or any complications involving the lungs, heart or eyes.

• Third, you have to be on an acceptable medication such as levothyroxine, liothyronine, liotrix or old fashioned pig thyroid extract (yeech!)

• Fourth, your lab test for low thyroid, Thyroid Stimulating Hormone level or TSH, must have been reported as normal within the last 90 days.

If the answer to all of the above is yes, you’ve passed the test and avoid the folderol of a Special Issuance!

Fly wisely. See you next month!

As always, comments, questions and suggestions are welcome: jdlakin@mnallergyclinic.com.