The thyroid function comprehension is core for getting to know hypothyroidism, a very prevalent disease in the overall population. The people may not know how likely it is that this disease affects their life or how widespread it is among them.
When a patient with this disease shows up to a doctor, this condition is straightforward to diagnose and treat. However, it could be potentially fatal in severe cases if the patient is not taking treatment. Therefore, in-depth knowledge of hypothyroidism is the key to avoid unwanted outcomes. Please, keep reading, you would obtain insights from a doctor’s perspective about the thyroid function and its relationship with hypothyroidism.
What is the thyroid?
The thyroid gland is a structure within the forefront of the throat that produces an essential molecule, a thyroid hormone. It is relatively small and has two lobes. The thyroid gland does not function alone; for thyroid hormone production, many factors take part in regulating the thyroid function. Despite small and its isolated location, this gland influences the whole body, as we will see further.
Two upper structures regulate the thyroid function from the skull; they are the pituitary gland and the hypothalamus, conforming an axis. First, the release of thyrotropin-releasing hormone (TRH) by the hypothalamus stimulates the pituitary gland to discharge the thyroid-stimulating hormone (TSH) that directly causes the thyroid gland to release thyroid hormones.
The thyroid function would end up on stable thyroid levels in the blood. However, a thyroid disorder would cause either an excess of thyroid hormone or a decrease in it. That is the aim of this article and the hyperthyroidism one, to explain, when it lowers or raises, respectively.
The thyroid gland production of the thyroid hormone relies on many factors. The first one, as you saw, is the stimulation by other molecules from upper structures. Then, there is the iodine element; the thyroid gland needs it for producing hormones. It can be found in food as inorganic iodide, which can be absorbed and used by the body. The thyroid hormone has two major types, T4 (thyroxine) and T3, and both are produced in the gland. Nearly all of the thyroid gland production is T4, which is not active, and just 1% the active form, T3. However, the T4 transforms into T3 thanks to the liver and kidney; this active form of the hormone produces all the gland’s effects.
What role plays the thyroid hormone in the body?
The thyroid hormone, as you just saw has two representatives, one that is inactive and mostly produced by the thyroid gland and the other, which is active and acquires its function capabilities by other organs like the liver and kidney, T4, and T3, respectively. For T3 to generate any effect on the body needs to join its receptor. Luckily, the receptor for this hormone is nearly in all the body, so when produced, it acts almost on every inch of body tissue.
The primary purpose of this hormone is to accelerate things, and I mean everything, including metabolism. T3 can rush things up, to generate energy, to speed up the heart, to burn fat, to stay alert. Mostly because this is some kind of chain reaction, the thyroid hormone does not do it all by itself. It triggers other hormones as the catecholamines thas produces the same effect. Nevertheless, remember that this is invariably a balance, the body is not always in acceleration, and it needs an adequate quantity of thyroid hormone to develop and maintain successfully. Therefore, when imbalanced, diseases arise.
What is hypothyroidism?
Hypothyroidism definition comprises a decrease in the thyroid hormonal level within the blood. This definition is an arbitrary call because the reference ranges of thyroid hormones tend to vary between testing centers and do not necessarily correlate with successful outcomes. The hypothyroidism definition is solely chemical. Not all people with hypothyroidism have symptoms, or if they have them, frequently are vague and unspecific.
Why is not enough thyroid hormone? The thyroid gland discharges the thyroid hormone, as you recently saw in strict regulation because of the loop. Various scenarios exist on which there is damage somewhere in the circuit that halts the thyroid function. First, there could be an underactive thyroid, a thyroid gland that is just not functioning well. Secondly, the pituitary gland could not be working adequately and not deliver the TSH levels the thyroid gland needs for functioning. Thirdly, the hypothalamus, for whatever reason, is not producing TRH; therefore, there would not be TSH, or thyroid gland final stimulation.
According to the source, I mentioned you there would be names for hypothyroidism. Primary hypothyroidism or overt hypothyroidism is when the problem is in the thyroid gland; in this scenario, the TSH hormone is increased, and the thyroid hormone is below the range. Also, there is subclinical hypothyroidism, it is just a step before developing primary hyperthyroidism, and its characteristic feature is normal thyroid hormone level with an increase in the TSH levels above the range.
Secondary hypothyroidism is when the damage is on the pituitary gland. And, tertiary hypothyroidism when the illness exists in the hypothalamus. These two sources together have the name of central hypothyroidism because the impairment’s location is in the skull, not in the gland. These two types of hypothyroidism only account for 1% or less of all the cases.
How many people does it affect?
The estimation is that it affects the four percent of the United States population, and this could be even more if subclinical hypothyroidism sums up. It also tends to grow over with time; the highest prevalence of the disease is among the elderly. The female population, as with all thyroid disorders, gets way more hypothyroidism than males. Similarly, hypothyroidism affects nearly five percent of all pregnant women, and even more, have subclinical hypothyroidism.
What causes hypothyroidism?
The causes of hypothyroidism follow a classification. Each type has its specific diseases, as I will explain further.
The most important cause of primary hypothyroidism that causes nearly all the cases is Hashimoto’s disease which is an autoimmune disorder that causes thyroiditis. Thyroiditis means swelling of the thyroid gland, that in this circumstance it will produce thyroid disease.
Hashimoto’s thyroiditis has a high concentration of proteins within the blood, autoantibodies, they attack thyroid cells, destroying them, and causing thyroid dysfunction. Surprisingly, in this autoimmune thyroiditis, tobacco smokers have lower concentrations of these harmful proteins, and after tobacco cessation, in some cases, it has been noted an increase in Hashimoto’s disease.
Other causes of primary hypothyroidism are postpartum thyroiditis; it affects women in their first year posterior to delivering their child in up to five percent of them—the subacute granulomatous thyroiditis, which is uncommon transient hyperthyroidism followed by transient hypothyroidism. And there is acquired hypothyroidism (or iatrogenic/drug-induced); this cause of hypothyroidism means several medications can directly cause thyroid hormone deficiency.
For the thyroid gland, iodine is essential to produce thyroid hormones. Therefore, iodine deficiency could end in hypothyroidism. In fact, this acquired hypothyroidism is the most common cause in countries where the food does not have iodine or in people that do not regularly consume it in their diet.
For secondary and tertiary hypothyroidism, several causes are possible, from drugs to tumors. They are rare, but always a possibility in the doctor’s mind.
What are the causes of pediatric hypothyroidism?
The children are another story when it comes to thyroid disorder with particular implications. The average is that one in approximately 3000 births could have congenital hypothyroidism, and it affects early in childhood. This means that they are born with hypothyroidism. This thyroid hormone deficiency is either because of the failure of the thyroid gland to grow normally or an abnormal thyroid hormone production. However, for little children, the most common cause of hypothyroidism remains to be iodine deficiency.
This situation is critical because children need the thyroid hormone to grow normally. So having hypothyroidism could damage cognitive development with consequences in the future.
What are the signs & symptoms of hypothyroidism?
The thyroid disease, which comprises hyperthyroidism and hypothyroidism, would have precisely opposite symptoms, because in one there is an overactive thyroid gland and, in the other, an underactive thyroid gland, correspondingly. So in this disease, hypothyroidism, what we would see is the result of an overall slow body function.
It is important to remember that there can be patients with hypothyroidism without any symptoms; therefore, when patients with the disease show symptoms and signs to the doctor, the name for that is clinical hypothyroidism.
Patients with hypothyroidism could have either mild or very severe and life-threatening signs and symptoms that could even carry death. As we saw, the most common reason for hypothyroidism is Hashimoto’s disease, so the most common signs and symptoms would be from this disease. Because of the wide-reaching capability that the thyroid hormone has, the symptoms and signs could exist in every body’s sphere. However, they are not specific to this disease.
The mild hypothyroidism would have common symptoms, and others not that common at all, but it is possible to have them. The more prevalent are fatigue, cold intolerance, weight gain, constipation, change in voice, and dry skin. The elderly tend to have fewer symptoms than the younger population. The other possible signs and symptoms include a change in vision, taste or hearing, myxedema, mood and memory problems, fertility issues, muscle weakness, joints pain, and hair loss. Very subtle symptoms, indeed, but hypothyroidism due to its high prevalence, it is always an option.
Severe hypothyroidism could have very alarming symptoms and signs. For example, there is myxedema coma, which is a deathly expression of the disease that could have mind alteration, slow heart function, and heartbeat rate, eventually causing organ failure and death.
What other health problems could you have because of it?
Untreated hypothyroidism and its relationship with cardiovascular problems are widely known. Hypothyroidism directly decreases heart function and causes overall heart injury. Also, there is a raise in all the factors that collaborate with heart problems. It includes hypertension, increased waist circumference, and dyslipidemia (blood cholesterol problems).
What are the possible complications of hypothyroidism?
Hypothyroidism, besides severe hypothyroidism, can yield a vast quantity of complications. And that is the matter; a thyroid problem can virtually affect every inch of tissue throughout the body because all of them require that essential hormone.
Hypothyroidism’s most clear complication is cardiovascular problems, although many others are a suggestion and currently under study. The possible complications constitute dementia, nonalcoholic fatty liver disease, dying of cancer, arthritis, kidney problems, and diabetes; besides, as I told you, the dangerous myxedema coma.
Furthermore, the link between hypothyroidism and thyroid cancer does not seem clear by now. Hyperthyroidism, for example, has a more apparent role on that matter, in contrast to hypothyroidism. Currently, what is clear is the role that plays the thyroid nodule, adenoma, and goiter finding, and an increased risk of thyroid cancer compared to the overall population.
How to diagnose hypothyroidism?
Fundamentally the definition and diagnosis of primary hypothyroidism are upon serum TSH above the reference range and free thyroxine (T4) levels below the range. The utilization of the term overt hypothyroidism is when a patient has the recently described hormone level, and also present symptoms.
It is normal that following a history and body examination by the doctor. Some symptoms elicit suspicion about hypothyroidism so that it would indicate the blood test. There are many commercial tests for measuring them; they are immunoassays. And, right now, in the medical world, this situation represents a real issue. To the point of recommending that only patients with clinical hypothyroidism should have the diagnosis of the disease. This concerning the variability of such ranges that tend to change with age, sex, or ethnic origin. Therefore, taking into accounts some factors that matter more, as symptoms and the possibility of complications would aid in handling the disease better. This case is still under continuous revision.
What is the treatment for hypothyroidism?
Treatment would rely on giving to the body what is lacking, hormone. The thyroid medication is levothyroxine, and it should be taken an empty stomach.
Symptoms and thyroid test confirmation of hypothyroidism is a prerequisite for starting thyroid medicine. After initiation of therapy, a careful follow-up must take place, every 4-12 weeks at first, and then every six months. The monitoring needs to be this way because of the hormone levels; it takes time for the thyroid hormone replacement to make an effect. Luckily, when the average hormone concentration within the blood stabilizes, a single yearly checkup will be more than enough.
However, thyroid hormone medicine is not all. The doctor must have on its mind all the possible complications and assess them. As you saw, there are plenty, mostly involving the heart. So medication for any of them is also a must.
What should I eat or avoid eating if I have this condition?
Hypothyroidism is a condition where there is a decreased thyroid hormonal level. And for producing, it is essential to have iodine from food. So, for helping these patients in the early stages of the condition as subclinical hypothyroidism, diets that contain mostly food with iodine result beneficial, however not in excess, and not in all the cases. Patients that are already taking levothyroxine typically have no requirements of taking any iodine supplementation or whatsoever.
A balance between all the food groups is essential as cereals, vegetables, fruits, fish, meat, etc. Also, the reduction of cruciferous vegetables and high-cholesterol food, for increasing others that are beneficial as fish, fruit, and vegetables. Remember that hypothyroidism also plays a role in dysregulating the metabolism, most of the fatty molecules as cholesterol. Therefore, it is crucial to have advice from professionals regarding how to handle the diet because an excess of iodine could be harmful to health as well. For more information about iodine supplementation, what food contains it, and what are its specifications, click here.
What should I do if I have symptoms?
Please take a look at this hypothyroidism symptoms checker. It will help you to assess how likely it is that your symptoms are because of this condition. It is free and would only take a few minutes.