Thyroid: what it is, where it is located, and what it is responsible for

The thyroid gland is a small organ on the front surface of the neck, on which metabolism in almost every cell of the body depends. Below is a calm breakdown: how the gland is structured, where to find it in the neck, which hormones it produces, and when it is time to see a doctor.

Thyroid gland: what kind of organ it is

It is an endocrine gland that stores iodine and produces iodine-containing hormones. Its shape is like a butterfly: two lobes are connected by a narrow isthmus. The mass of an adult gland averages 12–25 g, and in a newborn — 2–3 g.

The tissue consists of follicles: thyroid hormones are synthesized in thyrocytes, and C cells produce calcitonin. Diseases vary: enlargement of the gland (goiter), hyperthyroidism and thyrotoxicosis, hypothyroidism, nodules, thyroiditis, cancer.

What to remember: the thyroid is a small organ with broad influence, and its diseases are a group of conditions with different mechanisms.

Where the thyroid is located and what it looks like in the neck

The gland lies in the neck below the larynx, in front of the trachea, on the surface of the thyroid cartilage. The isthmus is located at the level of the second to third tracheal ring. A doctor can examine the neck to determine whether the gland is enlarged.

Each lobe is approximately 2.5–4 cm long, 1.5–2 cm wide, and 1–1.5 cm thick. A volume of up to 18 milliliters in women and up to 25 milliliters in men is considered normal; in women, slight fluctuations may occur in connection with the menstrual cycle. Behind, on the posterior surface, four small parathyroid glands are usually located.

What to remember: the landmark is the neck below the Adam's apple; the size and volume of the gland are individual, and normal volume values differ in women and men.

Which hormones the thyroid gland produces

The main hormones are thyroxine (T4) and triiodothyronine (T3). They regulate metabolism and energy, growth, and maturation of tissues and organs. Calcitonin from C cells is involved in calcium metabolism and in bone formation.

The parathyroid glands produce parathyroid hormone — it regulates the levels of calcium and phosphorus salts in the blood.

What to remember: T3 and T4 are responsible for metabolism, calcitonin — for bones, parathyroid hormone — for the balance of calcium and phosphorus.

What the thyroid gland is responsible for and what it affects

Thyroid hormones control how the body uses energy. They affect almost every organ: breathing, heart rate, weight, digestion, and mood.

In women this is also noticeable in the cycle: when hormones are lacking, periods may be irregular or heavy. During pregnancy, untreated hypothyroidism increases the likelihood of complications — high blood pressure (preeclampsia), developmental defects, preterm birth, and miscarriage; treatment usually helps prevent them.

What to remember: the whole body "hears" the thyroid — the heart, digestion, bones, and reproductive system.

How the thyroid gland is connected with other organs

Digestion is one of the functions dependent on thyroid hormones; in hypothyroidism, constipation is a common symptom. The heart and bones are also sensitive: if hormone deficiency is not treated, the risk of cardiac problems, including coronary artery disease and heart failure, and bone problems, including osteoporosis, increases.

When to see a doctor

• marked fatigue and chilliness;
• weight gain and constipation;
• difficulty concentrating, low mood, or depression;
• dry skin, dry hair or hair loss, hoarse voice;
• irregular or heavy periods.

Symptoms develop slowly and intensify gradually, and many of them also occur in other conditions. The doctor will ask about complaints, about thyroid and autoimmune diseases in the family, about recent pregnancy, examine the neck, may order a blood test for TSH and T4, and refer to a specialist; sometimes additional examinations are needed, including a biopsy.

What to remember: the list of complaints is a reason to talk with a doctor, but not for drawing conclusions on your own.

Thyroid problems by themselves are not a reason to call an ambulance. 103 or 112 — if, against the background of severe untreated hypothyroidism, a life-threatening condition develops (myxedema coma); it occurs very rarely and requires treatment in a hospital.

The material is for reference: it helps to understand the topic, but does not replace a doctor's consultation.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer