The thyroid gland is one of the organs involved in the hormonal regulation of human life. It is located in the region of the anterior wall of the neck, and is anatomically represented by two lobes and an isthmus between them. The shape of the thyroid gland resembles a butterfly. Despite its small size, iron takes on a significant amount of functional load on the production of hormones.
Location and structural features of the organ
The thyroid gland is located on the front surface of the neck, below the hyoid bone. Its lateral lobes are located at the height of the signular and thyroid cartilages. The lower pole of the organ is at the level of the fifth and fourth tracheal rings, and its weight reaches 30 grams in an adult.
The front of the gland is covered with skin, subcutaneous fatty tissue and four fasciae: superficial, second fascia (surface plate), tracheal fascia plate of the neck with sublingual muscles. The sternum-hyoid muscle is the most superficial of all, and the sternum-thyroid muscle is underneath.
In a fixed position, the thyroid gland is supported by a ligament - a thickening of the pre-tracheal plate of the fascia of the neck, which secures the organ to adjacent cartilages and trachea. Under the muscles and the third fascia is the parietal plate of the fourth fascia, fused with it. In the direction of the midline of the neck with the superior fascia, the second grows together, and together they form a white line of the neck.
Further, behind the parietal leaf of the fourth fascia there is cellulose of the interfascial suprasternal space, which is limited by the visceral leaf of the fourth fascia, which forms the capsule of the thyroid gland - its protective outer shell surrounding the organ on all sides. Under the capsule, around the gland itself there is friable fiber with vessels and nerves passing to the gland. The capsule is not connected closely and directly with the gland, due to which, for example, during surgery, cutting the capsule can move the thyroid lobes. In addition, the body has an internal fibrous capsule, directly connected with parenchyma septum.
The upper pole of the lateral lobes of the thyroid gland reaches the level of the middle of the height of the cartilaginous thyroid plates, and the lower pole descends under the isthmus and to the level of the fifth and sixth ring, 2-2.5 centimeters higher than the cutting area of the sternum.
About a third of the world's population has a pyramidal lobe of the gland. Additional shares are even less common. Pyramidal rises on the top of the isthmus, or from the side lobes. The isthmus is located in front of the trachea, in rare cases, the anatomical features of the structure of the gland do not imply the presence of an isthmus.
Connective tissue septa, which extend from the capsule to the parenchyma, divide it into lobules, in turn, consisting of follicles. The follicular walls are lined from the inside with a single-layer cubic epithelium. Inside the follicular cavities there is a liquid colloid with ribonuclein, proteides, iodine, thyroglobulin and other enzymes in the composition.
Features of blood supply and thyroid function
The organ is supplied with blood through four arteries - the two upper ones, departing from the external carotid artery, and the two lower, departing from the thyroid section of the subclavian artery. The fifth unpaired artery is found in rare cases, and departs from the nameless artery or aortic arch. Accordingly, a person has a similar number of paired veins.
The innervation of the organ is due to the sympathetic and parasympathetic nerves.
One of the main functions of the thyroid gland is the secretion of iodinated hormones:
The basis for the formation of hormones is iodine and the tyrosine amino acid. Iodine enters the body with food, air, water in the form of inorganic or organic compounds. Excess element is excreted with bile and urine. In the blood, its organic compounds form sodium and potassium iodides, and under the influence of oxidation by enzymes they turn into iodine.
Thyroxine is a thyroid hormone that affects metabolic processes and regulates the processes of development and growth in the body. In the cells of the brain, oxidative reactions occur with its participation. The imbalance of its concentration causes the development of various pathologies - myxedema, cretinism. In addition, protein production processes are directly dependent on the amount of thyroxine.
Triiodothyronine is released during the process of thyroxin deiodination in the liver and kidneys. The thyroid gland also produces it, but in smaller quantities.
Due to the production of iodized hormones in the body, the thyroid gland affects:
- the functioning of the central nervous system;
- higher nervous activity;
- growth, development of the body;
- the vegetative system (muscle contraction, respiratory movements, sweating processes);
- the ability of blood to clot.
Calcitonin (thyrocalcitonin) is a non-iodinated hormone, that is, not containing iodine. Its amount directly affects the amount of phosphorus and calcium in the blood, and under its influence the amount of these substances decreases. The hormone is formed by parafollicular thyroid cells located outside the follicle.
All produced hormones are involved in metabolic processes to maintain vital activity, and also affect the functioning of the digestive organs, respiratory, reproductive and nervous systems.
Thyroid enlargement: what is it and why does it appear
In normal condition, the organ is not visible to the eye, and cannot be felt by the fingers. However, there are some pathologies in which an enlargement of the thyroid gland occurs, sometimes to such a size that a person has a large goiter on the neck.
Gland enlargement is a common disease that affects people of various age categories. It is dangerous in that it can not always be detected in the initial stages, and changes that occur in the body due to changes in the normal size of the gland may be the beginning of irreversible processes.
An enlarged thyroid in itself is not always a pathologically dangerous condition, and not even in all cases requires emergency treatment - it all depends on the etiology of the condition.
Doctors distinguish several stages of changes in the size of the organ:
- Stage 1: normal, no changes;
- Stage 2: the thyroid gland has increased in size, however, it is not visible during examination, it does not deform the neck, the organ can only be felt;
- Stage 3: the increase is noticeable with the naked eye, especially when turning the head, it deforms the contours of the neck.
In addition, the degree of thyroid enlargement is known:
- 0 degree: no increase or a slight increase, in which the organ is not visible to the eye, and is not palpable;
- 1 degree: the isthmus is determined by palpation, the organ is not visible visually;
- 2 degree: both lobes and isthmus can be felt, the organ becomes noticeable when swallowing;
- 3 degree: noticeable visual increase, the neck becomes because of this more rounded in appearance;
- Grade 4: entails a change in the shape of the neck, the lateral parts of the organ extend beyond the outer edge of the sterno-mastoid muscle;
- 5 degree: large, well-marked goiter, which apparently deforms the neck.
According to the 2010 International Classification of Diseases (ICD 10), pathology is indicated by the code E00-E07 - thyroid disease.
Causes, degrees and stages of organ enlargement, manifestations of pathology
There are various reasons for the change in the size of the organ in a big way, among which doctors often mention:
- lack of iodine, selenium and fluoride in the diet (especially in children);
- the influence of negative environmental factors, for example, toxic or radioactive substances;
- the presence in the blood of substances that interfere with the production of thyroid hormones (aminosalicylic acid, resorcinol, sulfonamides);
- lack of vitamin D;
- viral and bacterial lesions that inhibit the thyroid gland;
- chronic stress;
- lack of physical activity;
- hereditary predisposition;
- diseases and malformations of the hypothalamus and pituitary gland, which work in direct conjunction with the thyroid.
Such causes and diseases become a catalyst for the development of various pathological syndromes associated with organ enlargement:
Hypothyroidism is a state of insufficient production of thyroid hormones as a result of iodine deficiency. Against this background, the organ begins to work more intensively, respectively, grows in volume. Pathology can be primary or secondary: in the first case, the condition develops as a result of malfunctions of the thyroid itself, in the second, due to hypothalamic and pituitary diseases, and also due to a lack of thyroid stimulating hormone of the pituitary gland.
Hyperthyroidism is characterized by increased secretion of hormones, due to which its concentration exceeds normal values. It usually develops against the background of toxic diffuse goiter (Bazedovo disease), inflammation of the thyroid gland, tumor neoplasms in it, in the hypothalamus or pituitary gland. The condition is accompanied by increased metabolic processes.
With euthyroidism, the thyroid gland is enlarged with normal hormones, that is, the results of tests for thyroid hormones do not show any deviations. This pathology develops as a consequence of the compensatory function of the body - in this way it tries to cope with a lack of iodine. The pituitary gland intensely produces thyroid-stimulating hormone, thus supporting the functioning of the thyroid gland.
Euthyroidism is a condition that occurs in adolescents during puberty, as well as in pregnant women, and in women with menopause. It can also form as a side effect of taking certain medications.
How to determine if euthyroidism is a disease or not? Doctors call this condition borderline between norm and pathology - that is, functional changes in this case may develop, but not necessarily in each case. You can talk about the presence of pathology only if there is growth of the thyroid gland, but at the same time the level of hormones produced by it remains stable.
For diagnosing syndromes of euthyroidism, hypo-and hyperthyroidism, physicians resort, in addition to the initial examination and questioning, to the appointment of an ultrasound of the thyroid gland, and also necessarily send the patient to take tests for thyroid hormones. If the results of the ultrasound examination are not enough, the patient may be prescribed an MRI and radioisotope diagnosis. Usually, when euthyroidism is detected during pregnancy or in a teenager, special therapeutic measures are not prescribed - doctors prefer monitoring the condition and work of the organ.
Typical varieties of the glandular enlargement process
An increase can occur in several types. So, the presence of diffuse goiter indicates a uniform change in the size of the organ, and nodular enlargement occurs with the formation of local nodes throughout the gland. At nodular increase, against the background of iodine deficiency, thyrocytes partially go out of control of the thyroid-stimulating hormone produced by the pituitary gland, as a result of which the nodes are formed (seals similar to tumor formations that increase the total volume of the organ). If a fluid accumulates in the node, it is considered that the patient has a cyst. This type of goiter is more often found in people over the age of 50.
Another classification of pathology is for the reasons that provoke it. Depending on the etiology, goiter may be:
Endemic goiter is formed as a result of a lack of iodine in the environment surrounding the body, while sporadic goiter develops in those people who have everything in order with the amount of iodine in their diet. Like endemic, it can be nodular, diffuse, or mixed. Its development is provoked by environmental factors, poor ecology, exposure to radioactive substances, hereditary predisposition.
In addition to visual changes in the contours of the neck, changes in the organ can be detected by palpation, paying attention to changes in its density, on its mobility. Normally, an organ has an elastic and soft texture. When swallowing, it normally moves with the cartilage.
Symptoms of pathology: how to detect a disease
In what cases can one suspect an enlarged thyroid gland? The development of a pathology in a person, most often, is accompanied by the appearance of certain symptoms.
The first signs of deviations in the work of the body are:
- weight fluctuations: an increase or decrease in body weight for no apparent reason may indicate that the gland produces insufficient hormones, or, conversely, too many hormones are secreted;
- visual change in the contours of the neck: when a medium or large goiter is formed, it becomes more rounded, powerful, the goiter can act as a big ghoul;
- violation of the heart rhythm: hypothyroidism provokes a stable slowing of the heartbeat in the affected person, hyperthyroidism - its acceleration;
- reflex cough: if the gland sharply or gradually increases, it begins to occupy more volume than normal and interferes with normal breathing and the swallowing process, causing in some cases a sensation of a lump in the throat;
- decreased body tone, a feeling of chronic fatigue: a person in this case feels lethargic, irritable, he has trouble sleeping, changes in behavior;
- hair loss: causeless thinning of the hair should alert, since the problem may not be the lack of vitamins, which are usually sinned on in the first place;
- sensation of heat and chills: pathologies of the thyroid gland are directly reflected in the processes of thermoregulation of the human body, therefore, due to hypothyroidism, the patient can often and without reason throw in chills without an increase in temperature, and with hyperthyroidism - in heat with severe sweating.
In addition, a person should be alerted to the sensation of pain when swallowing food or swallowing saliva - this may be a sign of the formation of nodular formations in the organ parenchyma. To the touch, an enlarged thyroid gland is dense and solid. During swallowing, it does not move, although normally it should move freely along with the cartilage. When pressed, pain may not be felt, but palpation is usually accompanied by discomfort.
You should also pay attention to such symptoms:
- dry skin and brittle nails;
- constipation or diarrhea;
- numbness of fingers or tingling in them;
menstrual disorders in women;
- vision problems;
- muscle weakness.
Are the lymph nodes connected to the thyroid gland? Of course, those lymph nodes that are located in close proximity to the body can respond to changes in its work. Inflammation of the lymph nodes is a symptom characteristic of inflammatory thyroid disease. It is also observed when new growths appear in the organ.
An increase in the proportion of the body: why it happens
It is known that the thyroid gland consists of the right and left lobes, sometimes additional lobes are also formed in it. Normally, the right lobe is always slightly increased in relation to the left. The normal weight of the thyroid gland in average is about 30 grams.An increase can occur not only in the entire volume of the organ, but also in a separate lobe, especially against the background of the inflammatory process or the formation of a benign cyst.
Multiple cysts are rarely diagnosed, basically, they have a single character.
With an increase in the left lobe of a patient, pathological processes and diseases are suspected. The most common cause is precisely the cyst of benign nature. The sizes of cysts reach up to 3 centimeters - such formations do not respond with pain. If the cyst grows more than 3 centimeters, it already hurts the affected person. This is due to the fact that an expanding cyst squeezes the organs located next to it with the left lobe. In addition to pain, the patient has hoarseness in his voice, cough, sore throat. There is an asymmetric change in the size and shape of the neck - a growing increase appears on the left side.
Changing the size of the isthmus thyroid
An increase in the isthmus of an organ is a rare occurrence, but it always indicates that pathological changes occur in the thyroid gland.
The isthmus is a junction of the left and right lobes. It is located in the area of the second and third trachea cartilage. In some cases, the isthmus is at the level of the arc of cricoid cartilage or the first tracheal cartilage. The normal isthmus is an elastic, painless fold with a flat and smooth surface.
The main reason for the increase is hormonal changes in the body. The problem may be the proliferation of metastases from closely located organs, or from the lobes of the thyroid gland.
The development of pathology in women, men, children
Why an enlarged thyroid in women
In women, the thyroid gland is somewhat more prone to size changes due to the frequent hormonal interruptions to which they are prone.
In a woman’s body, thyroid hormones are responsible for all regulatory functions, physiological processes, and metabolism. If the body is not able to cope with the load, a hormonal malfunction begins in the human body, and the woman notices a menstrual cycle, delay, difficulty conceiving a child. The affected person feels trembling in her hands, her condition worsens, her hair falls out and dull, her nails break.
An increase in the thyroid gland for a woman negatively affects the course of puberty, pregnancy, menopause. During pregnancy and during childbirth, the organ of a woman is especially vulnerable, and to save it from stress, and the body from infection, from a decrease in immunity and iodine deficiency.
Enlarged thyroid in men
Pathology appears less frequently in men, since their thyroid gland has a slightly different anatomical structure. So, even the initial stages of an increase in a man can be immediately visually noticed, and for this you do not need to do an ultrasound or go to an endocrinologist.
Hyperthyroidism in men is manifested in a sharp weight loss, a change in behavior - the affected person becomes more excited, talkative and restless. His fingers tremble, intense sweating, weakness, impaired sexual function, and arrhythmia develop. All this happens against the background of a goiter growing on the neck.
Hypofunction of the organ is accompanied, in addition to thickening of the neck, increased fatigue and high blood pressure, constant chills and an unreasonable increase in body weight. In addition, there is erectile dysfunction.
Another type of thyroid enlargement is associated with the development of thyroiditis with rapid progression. The patient has an increased sensitivity to low temperatures, difficulties with swallowing movements, and even early gray hair is manifested. This disease has a tendency to hereditary transmission, and negatively affects the reproductive function of the affected.
Children's pathology development
An increase in the thyroid gland in a child is a common abnormality. The main reason for the occurrence lies in the lack of iodine in the food and consumed fluid, which is superimposed on the hereditary predisposition.
In addition, the disease can develop in children living in ecologically unfavorable areas, for example, with an increased level of radioactive particles in air, soil, water.
At the beginning of the appearance of pathology, it is difficult to detect it in a child, since it proceeds unnoticed. Symptoms of the disease are gradually increasing - weakness, drowsiness, abnormal weight fluctuations, up or down. Drowsiness alternates with insomnia, body edema, shortness of breath, irritability. Such manifestations are often attributed to seasonal lack of vitamins, or age-related changes.
Prevention means a periodic visit to the doctor, starting from infancy.
Diseases of the thyroid in adolescents
For this age category, an increase in the thyroid gland is an urgent problem that appears as a result of hormonal age-related changes and puberty. Hereditary predisposition, the presence of congenital diseases, iodine deficiency plays a significant role in this process. Symptoms have similarities with pathology in children and adults.
Due to the increased need of the body and a lack of iodine, other vitamins and minerals, a teenager may develop sporadic and endemic goiter. Diffuse toxic goiter appears in people during puberty, and develops against the background of infectious diseases, chronic infectious processes in the nasopharynx, and hereditary predisposition.
The consequences and complications of the disease
Like many other pathologies and diseases, an enlargement of the thyroid gland rarely goes away without negative consequences. They can be reversible, or provoke irreversible changes.
As a result of an increase in the thyroid, the patient has disorders and digestive disorders, loss or weight gain, insomnia, which is replaced by sleepiness, and hypersensitivity to temperature fluctuations.
Increased production of thyroid hormones provokes an acceleration of all processes in the body, and increased intestinal motility, resulting in diarrhea. Accordingly, with reduced synthesis of hormones, peristalsis slows down, and the patient has constipation, bowel distention.
Excessive concentration of hormones in the blood also speeds up the metabolism, and a person quickly loses weight. Against this background, sleep disturbance appears, and in a few days the patient can sleep for only a few hours. At the same time there is an increase in body temperature, heavy sweating. The lack of thyroid hormones, on the contrary, causes weight gain, drowsiness, decrease in temperature and a constant feeling of chills.
In addition, the effects of an enlarged thyroid are:
- feverish conditions;
- violation of clarity of consciousness;
- disorders of the functioning of the central nervous system;
- dysfunction of hearing, sight;
- disruption of the respiratory system.
If the disease is not adequately treated, it can turn into serious complications and conditions. Patients in some cases develop hypothyroid coma or thyrotoxic crisis. With coma in the affected body temperature drops below 35 degrees, and the brain begins to suffer from oxygen starvation. A crisis, on the contrary, is accompanied by a high temperature (up to 41 degrees), delusions and hallucinations, a decrease in blood pressure. Both conditions can result in the death of the patient.
Treatment of an enlarged thyroid gland
The treatment process begins with diagnostic measures to find out what caused the onset of thyroid disease. In addition, the attending physician must establish the degree of increase, its stage, the level of its functioning disorder, determine the final diagnosis.
First of all, therapeutic therapy involves the appointment of hormonal drugs to the patient. If hormonal indicators according to the results of analyzes are normal, the patient is assigned to monitor and monitor his health. It is imperative that you conduct an ultrasound scan of the thyroid every 2-3 months.
In the most dangerous cases, the affected person needs surgical intervention, sometimes removing part or all of the thyroid gland. After surgery, a person is prescribed hormone therapy for the rest of his life.
In addition, topical methods of treatment are the administration of iodine containing drugs such as Iodomarin, therapy with radioactive iodine, and the appointment of means to reduce the production of hormones by the thyroid gland.
Substitution therapy involves mainly the use of the drug L-thyroxine. The dosage of the substance must be developed individually for each case. At the beginning of therapy, the drug is taken in small doses, but gradually the dosage increases by the middle of the course. The total duration of the course of treatment with hormones ranges from several months to two years. In the process, there is a noticeable reduction in the size of the organ, and in the absence of nodes, the return to normal size occurs very quickly.
If the patient is diagnosed with hyperthyroidism, he is prescribed drugs to reduce the production of hormones - metizol, tiamazole, tyrosol.
Is it possible to treat an enlarged thyroid using folk remedies? As the doctors say, the recipes of traditional medicine can be an addition to the general medical therapy, but they cannot fully replace the qualified medical assistance. To normalize the work of the body, decoctions of chamomile, berries and leaves of red and aronia, decoctions of partitions of walnuts are used.
A prerequisite for recovery is adherence to the principles of a balanced diet. For the normal functioning of the gland, the presence of iodine-containing products in the diet is important - seaweed, currants, dates, persimmons, apples. In some cases, the patient is prescribed a special therapeutic diet.
The process of enlarging the thyroid gland can not always be seen visually, or felt in the process of normal life. For example, a moderate increase in size at first can be detected only by the results of ultrasound, since more obvious external symptoms increase gradually. The appearance on the front surface of the neck of a large ghoul, which gives tenderness to palpation, interferes with swallowing and feels like a lump in the throat, indicates a large increase in the size of the organ, and this symptom is easier to notice.
In any case, if you detect manifestations of an enlarged thyroid, even slightly, you need to contact an endocrinologist.