Regular checkups

When you first begin thyroid hormone medication, you need to have your levels of thyroid hormone checked every month or so, until the doctor is satisfied that you are getting the precise dosage of hormone your body requires. Once your symptoms improve, schedule a visit with your doctor every 6 to 12 months — your requirements for thyroid hormone might change over time. This is also true if you have a mild thyroid condition that does not require medication or if you are one of the few people who have been successfully treated for overactive thyroid without becoming hypothyroid. Some people in this group do eventually become hypothyroid many years down the road, so it is important to schedule checkups at least once a year.

When you're feeling good and leading a busy life, it's easy to put these checkups low on your list of concerns. But keep in mind that a number of factors can affect your thyroid hormone levels: stress, increasing age, changes in your diet, or pregnancy. You may need an adjustment in medication periodically.

Healthy eating and exercise

There is no special diet you must follow while on thyroid hormone medication, with a couple of exceptions. Avoid foods high in soy protein, which can interfere with the absorption of thyroid hormone. If your thyroid was not removed or destroyed and you still have a substantial portion of your thyroid, avoid excessive amounts of iodine, either in medications or supplements, as this could trigger more problems with your thyroid. Most iodine-rich foods, such as iodized products or fish, are acceptable, but kelp and other thyroid supplements should be avoided (see "Myth and fact: Kelp supplements" above). Aside from these restrictions, you are free to eat whatever you want, but as always, adopting a healthy diet that includes lots of fruits, vegetables, and whole grains is an important part of healthy living.

Eating a nutritious diet not only contributes to the renewed good feeling you experience once your thyroid levels are normal, but it helps your digestive system function smoothly and your heart pump efficiently — both of which support a healthy metabolism. If you still aren't feeling good despite your medication, improving your diet and beginning an exercise program may help. Here are some tips for healthy living:

Eat nutritious foods. Soft drinks, potato chips, candy, crackers, and other junk foods that are high in calories and low in nutrition have become a mainstay of the American diet. If you normally eat a lot of these foods, minimizing them or cutting them out altogether and replacing them with a variety of fruits, vegetables, and whole-grain foods could make a difference in your overall health.

Cut down on "bad" fats. Certain dietary fats contribute to heart disease and some forms of cancer. The Food and Nutrition Board of the National Academy of Sciences has recommended a range of 20%–35% of daily calories from fat of all kinds, reducing saturated fats and trans fats to a minimum. Saturated fats, which come mainly from animal products such as meat and cheese, and trans fats, which take the form of hydrogenated oils in manufactured food products, should both be minimized because they raise levels of LDL cholesterol. LDL cholesterol, also known as "bad" cholesterol, can build up in the inner walls of your arteries and form plaque that can clog these arteries.

Most processed foods and snacks contain trans fats, so you may be consuming them without realizing it. Instead, choose fats that help reduce LDL cholesterol. These include monounsaturated and polyunsaturated fats, from vegetable oils, and omega-3 fats, found in certain kinds of fish. Seeds, nuts, and legumes are also healthy choices.

Carbohydrates, the source of great debate these days, should fall in the range of 45%–65% of your daily calories. Stick with complex carbohydrates found in whole-grain foods, fruits, and vegetables, and avoid heavy reliance on white starches and sugars. Protein should make up about 10%–35% of your diet. Most people in developed countries get plenty of protein in their diets.

Cut down on cholesterol. The American Heart Association recommends limiting dietary cholesterol to no more than 300 mg a day. If your cholesterol levels are high, try to consume no more than 200 mg per day. Sources high in cholesterol include animal fat, eggs, and full-fat dairy products.

Increase dietary fiber. Dietary fiber helps improve digestion. Eating whole-grain foods and a variety of vegetables and fruits helps ensure that you have an ample supply of dietary fiber. The Food and Nutrition Board recommends men ages 50 and younger get 38 grams daily; men over 50, 30 grams daily; women ages 50 and younger, 25 grams; and women over 50, 21 grams.

Exercise. People who exercise tend to live longer because exercise increases the heart's pumping ability and the body's oxygen use, which provides extra energy and stamina. It also burns calories and can help keep your weight down. Just walking 30 minutes a day on most days can help prevent heart disease and stroke and promotes general good health.