Low Thyroid: What is it? Causes, Symptoms, Diagnosis and Treatment

This gland is a butterfly-shaped organ found in the center of the neck.

It creates and stores hormones that control the body’s heart rate, blood pressure, and metabolism (how the body produces energy from food).

Low thyroid is when the thyroid gland is underactive and does not release thyroid hormones necessary for human metabolism.

The thyroid gland releases typically necessary hormones transported through the bloodstream to receptors located throughout the body.

The alteration in thyroid function causes health problems.


Low thyroid causes include:

Inflammatory thyroid disorders

The most common cause of low thyroid in adults is Hashimoto’s thyroiditis, which causes long-term thyroid gland inflammation.


This disease damages the thyroid tissue, so the gland cannot function properly.

When the patient has Hashimoto’s thyroiditis, the body begins to attack itself by producing antibodies that attempt to destroy the thyroid gland.

Diet deficient in iodine and selenium.

There is a low intake of nutrient-rich foods and deficient iodine and selenium.

These are essential minerals for thyroid function and increase the risk of thyroid gland disorders.

These nutrients also play other protective roles in the body.

For example, severe selenium deficiency increases the incidence of thyroiditis because it stops the activity of a potent antioxidant known as glutathione, which usually controls inflammation and combats oxidative stress.

Hormonal imbalances

In some rare cases, the pituitary gland, which produces stimulating thyroid hormone, can cause changes in the levels of hormones in thyroid function.

Leaky gut syndrome or intestinal-type poisoning

Food sensitivities or allergies, including those related to gluten and dairy, can trigger intestinal inflammation.

Among other causes that can cause intestinal problems are:

  • Stress levels
  • An excess of toxins in the diet and the environment
  • Imbalances produced by bacteria

When a leaky gut occurs, small particles that usually get trapped within the heart begin to leak into the bloodstream through tiny openings in the intestinal lining, creating an autoimmune cascade and negative symptoms.


Although it is not very common, babies are sometimes born with a genetic condition called congenital hypothyroidism, caused by a dysfunction of the thyroid gland.

Some tests show that people are more likely to develop a low thyroid if they have a close family member with an autoimmune disease.


Although the exact cause is unknown, some women produce very high levels of thyroid hormones, followed by a very rapid drop in thyroid hormone levels when pregnant.

It is causing a condition called postpartum thyroiditis.

Symptoms often go away in 12 to 18 months, but they can also lead to permanent hypothyroidism.

Interactions of certain medications

Specific medications appear to lead to the development of an underactive thyroid frequently.

The most common include drugs to treat cancer, heart problems, and certain psychiatric conditions.

High levels of emotional stress

The stress affects hormones and is known to worsen inflammation.

Stress can raise cortisol and adrenaline levels, disrupting neurotransmitter function and worsening thyroid disease symptoms.

These include low energy levels, bad mood, low concentration, impaired appetite, weight gain, and the inability to get a good night’s sleep.

Symptoms of a low thyroid

The thyroid gland has been considered a “master gland.”

In addition to producing crucial hormones, it also helps to control the metabolic process, supporting the conversion of nutrients present in food into sound energy for the maintenance of the body and the ability to burn calories.

These hormones produced by the thyroid are essential in the breakdown of cholesterol, controlling fat triglyceride levels that circulate through the bloodstream.

For this reason, the changes that occur in thyroid function are the cause of heart problems.

One of the notable effects of low thyroid is mood swings accompanied by states of depression and anxiety, poor sleep and low immunity, and slowing down metabolism, resulting in fatigue and weight problems.

A myxedematous coma, caused by low thyroid, is characterized by a decreased mental state of the patient, hypothermia, and slowing of various organs.

Thyroid nodules are an accumulation of cells within the thyroid, creating an atypical mass.

Thyroid nodules are not usually dangerous, but they may turn cancerous.

Other symptoms that may occur are:

  • Sterility.
  • Feeling cold
  • Constipation.
  • Muscle pains.
  • Stiffness and inflammation in the joints.
  • Hair loss.
  • Cracked and rough-looking skin.
  • Trouble breathing.
  • Changes in the length of the menstrual cycle.
  • Cold or flu are more common due to low immune function.

Low thyroid, if left untreated, can become a hazardous condition.


Several thyroid tests can be done to get a better idea of ​​what’s going on in the thyroid: standard blood tests for thyroid-stimulating hormone, T4, T3, TPO, and reverse T3.

In general, thyroid-stimulating hormone levels less than 0.3 mIU / L and free T3 levels less than 2.0 mg/dl can indicate thyroid problems.

In addition to these tests, you can consider the following subclinical hypothyroidism self-test, basically low thyroid that will not be detected in a blood test.

Every morning, the body temperature is taken. The average body temperature at rest taken in the morning is between 36.56ºC and 36.78ºC.

The average active temperature taken during the day should be 37 ºC. If the average of the three daily readings, in the morning, over ten days, falls below 37 ° C, then a low thyroid function may be suspected.

Low thyroid treatment

Low thyroid is usually treated with T4 medications like Synthroid, at least medically.

However, many parts of the thyroid “chain” can be broken and must be addressed.

For example, since T4 is converted to T3 (the active form of thyroid hormone) in the liver and intestine, it is crucial to ensure optimal health.

Furthermore, 90% of low thyroid cases are autoimmune (Hashimoto), which means that correcting the ultimate source of the problem (leaky gut) will be very important.

The thyroid can be helped with a good combination of nutrients such as iodine, selenium, zinc, and N-Acetyl-L-Tyrosine.

A typical conventional treatment method is radioactive iodine for patients with thyroid cancers.

Because the thyroid absorbs most of your body’s iron content, this concentrated radiation is supposed to successfully kill most diseased thyroid cells without damaging cells in the rest of the body.

Exercise and a healthy diet are vital to managing stress and neurological function related to hormone secretion.

Research shows that people who exercise regularly tend to sleep better, cope better with stress, and more often maintain a healthier weight, reducing some of the most significant risk factors and symptoms associated with low thyroid.