Thyroidism refers to alterations in the functioning of the thyroid gland, a small gland located at the front of the neck that plays an essential role in the body's physiological balance.

The thyroid produces thyroid hormones (T3 and T4), responsible for regulating metabolism—the way the body obtains and uses energy. These hormones influence key functions such as heart rate, body temperature, weight, mood, and energy levels.

These dysregulations can develop progressively and, in many cases, present non specific symptoms, making detection difficult without medical tests. 

The diagnosis of thyroidism is performed through clinical analysis that 
measures thyroid hormone levels and accurately evaluates the gland's function, facilitating early diagnosis and proper follow-up.

Thyroid gland: what is its function?

The thyroid gland is an endocrine organ responsible for regulating metabolism and plays a fundamental role in numerous bodily functions. It directly influences:

• Daily energy levels. 
• Heart rate. 
• Body weight. 
• Body temperature. 
• Mood.

The thyroid gland secretes the thyroid hormones triiodothyronine (T3) and 
thyroxine (T4), which regulate various metabolic proccesses in different body tissues. 

Types of thyroid alterations: hypothyroidism and hyperthyroidism

When thyroid hormone production is altered, it is known as thyroidism, which can manifest primarily in two ways: 

• Hypothyroidism: the thyroid gland produces an insufficient amount of thyroid hormones, causing a decrease in the body's metabolic activity. 
  
• Hyperthyroidism: the thyroid produces an excess of hormones, 
  accelerating metabolism. 

When the thyroid functions slowly (hypothyroidism): 

• Persistent fatigue. 
  
• Cold sensation. 
  
• Weight gain. 
  
• Dry skin and hair loss. 
  
• Mental slowness. 
  

When the thyroid functions fast (hyperthyroidism): 

• Nervousness or anxiety. 
  
• Goiter. 
  
• Palpitations. 
  
• Weight loss. 
  
• Heat intolerance. 
  
• Insomnia. 

What is analyzed to know if the thyroid is working correctly?

To evaluate the thyroid gland's status, clinical analysis measures different parameters to understand how the body is responding and how the thyroid is functioning as a whole. 

TSH (Thyroid-Stimulating Hormone) 

TSH is produced by the pituitary gland. Its function is to stimulate the thyroid to produce thyroid hormones. 

• When the thyroid underperforms, TSH usually increases to try to activate it. 
  
• When the thyroid overperforms, TSH usually decreases.

👉 Therefore, TSH is the first indicator that alerts to a possible thyroid imbalance. 

Free T4 and T3 

Thyroid hormones T4 and T3 are produced by the thyroid gland and fulfill essential functions in the body.

·       T4 is the main hormone secreted by the thyroid and represents the circulating form that, upon reaching specific tissues, is converted into T3, the active hormone.

·        T3 is the biologically active form of the thyroid hormone and exerts a direct effect on the cells and metabolic processes of the tissues.

👉 These values make it possible to know whether the thyroid is producing the appropriate amount of hormones and how these are influencing the functioning of the body.

Anticuerpos tiroideos

In some cases, the analysis includes the measurement of thyroid antibodies, which help identify whether the origin of the disorder is autoimmune, that is, whether the immune system itself is affecting the thyroid:

• Thyroid peroxidase antibodies (anti-TPO): High levels of these antibodies may be a sign that Hashimoto’s disease is causing hyperthyroidism.
• Anti-thyroglobulin antibodies (anti-TG): High levels of these antibodies may be a sign of Hashimoto’s disease.
• Presence of thyroid-stimulating immunoglobulin: These antibodies may be a sign of Graves’ disease