When the scale keeps creeping up, your energy dips despite sleeping eight to nine hours, and your body feels out of sync, yet your labs come back “normal,” it’s easy to feel like you’re the problem.
Dr. Amie Hornaman knows that feeling all too well. She spent years competing in fitness and figure competitions, tracking her macros, training twice a day, and doing everything the industry says should yield results. But during one prep cycle in her 20s, something was off. Despite going by the books, her weight began to climb.
“I was following everything perfectly, but I kept gaining weight, first just five, then 10, 15 pounds,” she told Muscle & Fitness. “My coach assumed I was cheating with doughnuts and pizza, but I wasn’t.”
Hornaman eventually dropped out of her competition. By then, she was also experiencing fatigue, brain fog, and hair loss. But when she sought help, she says multiple physicians attributed her symptoms to lifestyle factors or stress. So she kept searching for more answers.
How Six Misdiagnoses Led to A Lifelong Mission
Over the course of several months, as she kept getting more tired and feeling like “a shell of a human,” Hornaman says multiple doctors dismissed her. “Eat less and exercise more. Stop stressing out about it,” she remembers their guidance, noting “six doctors misdiagnosed me, blew me off, didn’t run the right tests, told me I was normal, told me I was fine.”
It wasn’t until the seventh doctor touched her throat and told her to swallow. “I feel a little something on your thyroid,” Hornaman recalls the doctor telling her, and ordering a full thyroid panel.
She was diagnosed with Hashimoto’s thyroiditis, an autoimmune condition in which the immune system attacks the thyroid gland. She was prescribed levothyroxine (Synthroid), a standard synthetic T4 medication. “I was hopeful that it would help. But after five months, I didn’t feel any different.”
Hornaman began researching thyroid physiology and discovered T3, the active form of thyroid hormone, which her body wasn’t converting effectively from T4. She left conventional care and started working with a functional medicine practitioner, who changed her medication and added T3. Hornaman slowly began to feel her energy and metabolism return.
“It took six months to a year to fully feel like myself again,” she said. “But the early improvements were noticeable.”
That experience led her to shift careers, study functional medicine, and now, as the “Thyroid Fixer,” she specializes in thyroid and hormone optimization for women, particularly those experiencing symptoms despite “normal” lab values.
Why Thyroid Dysfunction Is Missed in Fit Women
Hornaman’s case is not unusual. Thyroid dysfunction can be underdiagnosed, especially in active women whose symptoms are attributed to training load, stress, or age.
According to the American Thyroid Association, an estimated 20 million Americans have some form of thyroid disease, and up to 60% of them are undiagnosed. Additionally, women are five to eight times more likely than men to develop thyroid problems.
“High physical stress and low caloric intake are known stressors on the thyroid,” Hornaman explained. “It can trigger or worsen conditions like Hashimoto’s.”
In women, thyroid issues are also more likely to surface during periods of hormonal change, including postpartum, perimenopause, and menopause.
Understanding ‘Thyropause’ and Midlife Hormonal Shifts
Hornaman coined the term “thyropause” to describe thyroid changes that emerge during midlife but are often overshadowed by perimenopause.
“Hormonal fluctuations are stressors. In women over 40, those stressors can activate underlying thyroid dysfunction, especially if there’s a family history or prior immune issues,” she noted.
Symptoms like fatigue, weight gain, slowed recovery, and cognitive changes can appear in both perimenopause and hypothyroidism, making diagnosis more complex.
Bring a List to Your Doctor’s Visit
Hornaman explained that standard thyroid testing often includes only TSH (thyroid-stimulating hormone), which may not detect early or subclinical dysfunction. Hence, she encourages her patients to request a comprehensive panel that includes free T3, free T4, reverse T3, and thyroid antibodies.
“TSH is a brain hormone, not a thyroid hormone,” she said. “It gives part of the picture, but not the full story.”
She recommends patients bring a written list of symptoms and specific lab requests to appointments. “If your provider won’t order them or tells you they’re unnecessary, seek a second opinion.”
According to a 2021 study in Frontiers in Endocrinology, patient dissatisfaction with thyroid care is common and often linked to gaps in testing, treatment options, and communication.
Why T3 Matters
Levothyroxine (T4) is the standard first-line therapy for hypothyroidism. But Hornaman explains, like her, many patients are not able to efficiently convert T4 into T3, the active hormone. Research remains mixed on whether combination therapy is superior, but clinical guidelines acknowledge that some patients may benefit from a T4/T3 combination.
“In my clinic, 100% of my patients need T4 and T3 or T3 only,” Hornaman noted. “Zero does well on T4 only because it’s the inactive thyroid hormone.”
Lifestyle Considerations for Thyroid Health
Hornaman emphasizes that medication is only one part of managing thyroid function. Nutrition, sleep, stress, and training load all affect the balance of those hormones.
She highlights a few key nutrients that are involved in thyroid function, such as iodine, selenium, magnesium, and vitamin D. For women with autoimmune thyroid conditions, reducing inflammation may also improve symptoms. She says black cumin seed oil, for example, has been studied for its role in lowering thyroid antibody levels.
For Hornaman, thyroid hormone replacement is a lifelong solution. “You would have to pry my thyroid hormone medication out of my dead hands before I actually ever stopped it,” she said. “It gives me life.”
She often compares it to insulin for type 1 diabetes. “When we’re replacing a hormone that is no longer being properly made by your body, you can’t just stop. If you do, you’ll go right back into that low hormonal state.”
She also points out that thyroid hormone is not a band-aid, but a foundational therapy that can make other medications unnecessary. “Instead of needing an antidepressant, a statin, or a sleeping pill, we treat the thyroid. And then, all of a sudden, the depression lifts, cholesterol improves, sleep returns, and metabolism begins to function again.”
Her upcoming book, The Thyroid Fix, is due out in May and aims to educate women on navigating thyroid health with data, context, and agency. It’s a guide to understanding how thyroid hormones affect the entire body, and what to do when standard care doesn’t go far enough.
“You can’t assume that ‘normal’ means optimal,” Hornaman said. “You have to know what good feels like, and have the tools to ask the right questions.”
