People commonly have vague symptoms like unexplained weight gain, dry skin, hair loss, brain fog, generalized muscle aches and pains and suspect it is due to hypothyroidism or under-active thyroid. They get evaluated by their primary care provider looking for a diagnosis, treatment, and relief of concerning symptoms but in the end find out that their TSH (thyroid stimulating hormone) is normal. It can be very discouraging as they are left to deal with the symptoms but no answers or hope for relief. Medical providers may then suggest symptoms are due to depression, stress, poor sleep and unhealthy eating habits. Although those things can contribute to these symptoms a test of TSH alone does not sufficiently explore thyroid dysfunction.
Thyroid dysfunction is complex and often difficult to understand but I will try explaining it here.Remember this, hormones are messenger sent between organs and glands as a form of communication. Think of this like talking to your new neighbors. You want to invite them over for dinner, so you send a text, but they don’t respond. You decide even though it is very uncool and so last century that you will call them. Still no answer. Very perplexing…so you make some muffins and head overt o knock on the door. No answer. This is just insane, now you are offended.Here you are trying to be nice, and these a-holes are too good to even respond to a friendly welcoming gesture. Suddenly someone peeks out the door. You say, oh hello and smile. They respond with a greeting you don’t understand. It dawns on you. These new neighbors don’t speak English, after a little awkward gesturing and with the help of a surly teen who speaks both languages, kind of, you find out they also don’t answer their phone because of the language barrier. Although you were trying with increasing effort to communicate your attempts were sometimes understood but mostly not received and so they did not produce the desired effect. Now let’s apply that to the thyroid.
There is a structure in the brain, the anterior pituitary (this is you) that produces TSH (your invitation to dinner). The anterior pituitary sends TSH to the thyroid gland telling it to produce T4 and a small amount of T3, approximately 20%. The thyroid gland is your neighbor and the T4 and T3 would be the desired effect or responding to the invitation to have dinner. T4 converts to T3 and once T3 levels are optimal it signals to the anterior pituitary to stop making TSH (invitation received and responded to so you can stop texting, calling etc). In the body this is referred to as the negative feedback loop. The language barrier in the metaphor has multiple causes but is often due to endocrine disruptors that bind receptor sites so that the message cannot get through to the gland but that is another topic entirely.
In the case of hypothyroidism, we see a high TSH because the thyroid has not gotten the message to make enough T4 convert it to T3 to let the anterior pituitary know it can stop making TSH. If this feels still feels confusing that’s ok. Here is the important part, in medicine we are taught to treat hypothyroidism by giving oral T4. When we dot hat the TSH levels decrease. Perfect right? Now we feel better…but very often we don’t. Why not? The TSH is normal now but it is the T3, the most ignored part of this puzzle, that acts at the cellular level and is responsible for improving symptoms.
When we use T4 alone to treat hypothyroidism we see an increase in visceral fat which leads to higher BMI despite eating less calories, increased glucose (or sugar) levels, increased cholesterol levels, increased blood pressure and depression. People taking T4 alone, the most commonly prescribed treatment for hypothyroidism are more likely to also be taking a statin medication, beta-blocker and anti-depressant. One study found that low levels of T3, regardless of treatment with T4 are associated with high levels of cholesterol.
Wait just one minute, I hear you say, that doesn’t make sense. If the body converts T4 into T3 why wouldn’t treatment with T4 fix the problem? T4 will convert into T3, levels will rise, and problem solved! I knew you were very smart and a had a critical eye, thank you for asking. That is a reasonable hypothesis and it's what many endocrinologist also think but unfortunately t’s not what actually happens. When we give T4 and begin to suppress the thyroid, telling it to stop making TSH, the thyroid also stops producing the small amount of T3 it is responsible for making. Also high amounts of exogenous (or given from outside the body) of T4 just do not result in high T3 levels. In short, our treatment with T4 alone can actually make symptoms worse. It’s a frustrating experience for patients who continue to suffer with symptoms of hypothyroidism and for providers who can’t seem to find a way to help them.
The good news is there is new and old research out there proving that treatment with desiccated thyroid, a combination of T3 and T4 often leads to a resolution of symptoms and avoids or reverses the negative effects of T4 treatment alone. At Hummingbird Healthcare we aim to use the most up to date research to fully explore your individual concerns and make a plan tailored to you and all your healthcare needs.
