Understanding Your Thyroid (Continued)
What Can Go Wrong?
The sous-chef of the body's thyroid "system" is actually the pituitary gland, and the head chef is the hypothalamus. The hypothalamus monitors the levels of T-3 and T-4 in the body and if it finds them wanting, alerts the pituitary gland, which in turn tells the thyroid that the coffee break is over and to get the hell back to work. As you might expect, this complex hormonal ballet of one organ telling the next what to do can short circuit in a number of different ways.
In fact, when it comes to the diabetes-common low-thyroid, there are three different ways things can go wrong.
First, the gland itself may under-produce the primary go-juices of T-3 and T-4 that fuel the body, no matter how much it's told to make. This is called primary hypothyroidism, and is the most common of the three dysfunctions. Think of this as lazy line cook thyroidism. The sous-chef is shouting and screaming at the thyroid, right out of reality TV, but it does no good.
In other cases, the thyroid gland itself is as fit as a fiddle, but isn't getting the proper instructions from the sous-chef pituitary gland, which is supposed to "stimulate" the thyroid gland to produce the thyroid hormones. The signaling hormone between the pituitary and the thyroid is thyrotropin, more commonly called Thyroid Stimulating Hormone, or TSH. If the pituitary doesn't produce enough TSH it's called secondary hypothyroidism.
And of course the problem can be even farther upstream if the head chef is a drunk. The pituitary gland is signaled by the hypothalamus to release the TSH. The hypothalamus does this by using yet another hormone called thyrotropin-releasing hormone, or TRH. If this pathway breaks down, you have tertiary hypothyroidism.
You can see that this is a bit like one of those wheels in a hamster cage. If the thyroid isn't kicking out enough T3 and T4, the hypothalamus detects it, lets the pituitary gland know by releasing TRH, and that will in turn cause the pituitary to release more TSH. Why am I boring you with all of this? Because your doc will check your TSH level and, perhaps counter-instinctively, a high level of TSH is a signal of an under-preforming thyroid.
OK. I just saw your eyes glaze over on me. Look, it's just like type 2 diabetes. You can have crazy-high blood sugar and crazy-high insulin levels at the same time because the body doesn't use the insulin well. In this case, if the thyroid is asleep on the job the sous-chef is screaming at him to wake up and get to work, customers are waiting. A high level of TSH is the sous-chef screaming.
But, regardless of the exact cause of your lazy thyroid, the results are the same: Mind-numbing fatigue, chills, cold hands and feet, and weight gain. And that's if your thyroid is only a little bit sluggish. If the deficiency of T4 gets greater, you can suffer from dry skin, brittle hair, swelling of the throat, joint and muscle pain, altered mental status (usually impaired memory and the inability to concentrate, but this can also show up as uncontrollable emotional outbursts). Your heart rate can even drop to dangerously low levels.
Polypharmacy: the use of multiple drugs and medications in the same patient (person), usually to treat more than one medical condition. There's a lot we do NOT know about age-related deterioration of one's mental faculties. Every week, it seems, we hear another story where diabetes and age are concerned: one day we read that keeping glucose too high may cause dementia; the next, we hear that hypoglycemia may hasten that mental decline. Only one thing we can take...