Q: I’ve been struggling with weight gain and fatigue for years now and had many medical tests and examinations without any answers. After doing some research, I think the problem might be with my thyroid. My primary care doctor checked my thyroid levels, but they were normal. Is it possible I need a different thyroid test? Should I see an endocrinologist?
A: As an endocrinologist, I know many people have faced a similar situation. It’s true that an underactive thyroid (hypothyroidism) can result in fatigue, weight gain, constipation, dry skin, depression, muscle aches, impaired memory and increased sensitivity to cold. But these symptoms are not specific to hypothyroidism and there are many other possible causes.
Fortunately, there is a very simple, reliable and sensitive blood test that can determine whether you have hypothyroidism. It sounds as if you’ve already undergone this test of your thyroid-stimulating hormone (TSH). There is a myth that blood tests aren’t a reliable way to find thyroid disease, but this is not true. An abnormally high TSH will catch low thyroid function in about 95% of cases. The other 5% of cases can be detected with a TSH test and a test of free thyroxine (T4).
If both these values are within the normal range, you do not have hypothyroidism. Other tests of your thyroid function, such as serum free triiodothyronine (T3) or a test known as a reverse T3 will not provide new information that can change this diagnosis. Although endocrinologists specialize in hormone disorders including hypothyroidism, we refer to the exact same standard thyroid hormone tests that your primary care provider has already conducted.
You don’t want to be treated for hypothyroidism if you don’t have it. The most commonly used medication is a synthetic thyroid hormone replacement known as levothyroxine (Levo-T, Synthroid, others). For those with hypothyroidism, this medication generally doesn’t lead to side effects if taken at the correct dose, because it is identical to the body’s own T4 hormone. But if you don’t have hypothyroidism and take levothyroxine, it may lead to symptoms of high thyroid levels including anxiety or agitation, insomnia, palpitations, and shakiness. Those on thyroid medication must be monitored to make sure the levels are appropriate, which involves regular clinic and laboratory visits.
For some, the news that they don’t have hypothyroidism may be a relief. But for others dealing with chronic symptoms who understandably want a medical answer, this news may be discouraging. There are still options for you!
Your health care team can also check for other causes of your symptoms. For example, fatigue could be due to an autoimmune disease such as celiac disease, multiple sclerosis or lupus; problems with an organ such as your kidney, heart or liver; anemia; a mood disorder such as depression; or a sleep disorder such as obstructive sleep apnea. If you still don’t have clear answers or a therapeutic plan, an evaluation from a fatigue specialist such as can be found at the Mayo Clinic Fibromyalgia and Chronic Fatigue Clinic may be helpful.
It may also help to shift your focus from finding a diagnostic cause of your symptoms toward finding ways to alleviate those symptoms. This isn’t to say that your symptoms are “in your head” — they are real! But it can be very difficult or impossible to nail down a medical cause, and you may find relief from these symptoms and improve your quality of life with help from:
- An exercise program
- A registered dietician
- Cognitive behavioral therapy to help you learn techniques for coping with chronic symptoms
I hope these approaches are successful and that you find symptom relief!