Robin was looking forward to her appointment with me. After reading the discussion board on About.com she was convinced she had a thyroid problem. Now only could she not lose weight, she was so intolerant to cold that she had to bring a sweater with her everywhere she went. What drove her to make the appointment with me, though, was her severe fatigue.
“I’m constantly tired. My bowels don’t move, my hair is falling out and I’ve gained 4 dress sizes! I’ve been to a few doctors but they haven’t helped me. They said my lab tests are normal.” Robin continued, I’m a stay-at-home mom; I shouldn’t be this wiped out! I searched the internet and found a web site that described how low thryoid can cause all my symptoms and then saw the article you wrote on thyroid lab tests It was as if you were talking just about me!”
“Yes, Mary Shomon has put together a great resource for people suffering from thyroid problems. She asked me to write that article to explain why lab tests don’t always diagnose hypothyroidism correctly. Can I see your old blood work?”
I looked at the pages and instantly saw what was going on. “It looks like your other doctors were looking at one test called the TSH. Even though the lab still reports the old normal range of 0.5 – 5.5, your level of 4.87 isn’t normal. Since November 2002, the American Association of Clinical Endocrinologists has encouraged doctors to consider treatment for patients who test outside the boundaries of a narrower margin based on a target TSH level of 0.3 to 3.04.”
“Does that mean that I really do have a thyroid problem?”
“Most likely. However I think we should look a little deeper. I want to check for Thyroid Antibodies. When they are present, we call this Hashimoto’s Thyroiditis. Unfortunately, Hashimoto’s Disease makes blood tests for thyroid less accurate to where the TSH doesn’t correlate as well with symptoms. I first noticed this phenomenon in my residency where I had a patient with severe hormone resistance who required 400 mcg of Synthroid per day to feel normal. At lesser doses, she was severely fatigued. We had to check out her heart and bones periodically with EKG’s and Bone Density Scans, but at that dose, she felt fine without side effects or complications, despite having a low TSH.”
Robin asked another question, “So if you can’t always go by the TSH test, how do you know how much medication to use?”
“Just like psychiatrists who prescribe antidepressants empirically, I start low and go slow. I monitor my patients for improvement and any potential side effects. When my patients’ symptoms stabilize, they don’t need as close monitoring and I’m able to space out their visits.”
“One last question: If you do decide I have a thyroid problem, which medication would you choose for me?”
“Most doctors prescribe medications that contain only T4 such as Synthroid (levothyroxine). There are other medications that contain T3 such as Cytomel and Armour Thyroid, and I have found that some patients do better when I individualize therapy to each patient’s needs. For example, when a patient’s T3 level is low; they often do better with the more “natural” thyroid medications. Before we start, I’m going to check the free levels of your hormones.”
Robin’s antibody test did come back positive and she was started on thyroid hormone. Though her weight didn’t melt of instantaneously, her fatigue lifted and she was able to exercise. “Look at me,” she said, “I’m back to a size 8!”
