The Causes Of Low Thyroid Stimulating Hormone

The thyroid stimulating hormone is responsible for regulating the formation of hormones from the thyroid gland. If there is an imbalance, it manifests itself as problems such as hypothyroidism or hyperthyroidism.

The thyroid stimulating hormone (TSH) is a molecule that plays a role in any malfunction of the gland. This is why doctors ask for tests that measure the concentration of TSH in the blood when they find certain symptoms that have to do with this organ.

A low TSH indicates a change that needs to be investigated further. So this study is often the first of several others that follow.

What is the thyroid stimulating hormone?

TSH stands for thyroid stimulating hormone, or technically thyrotropin. It is secreted from the pituitary gland after the stimulus it receives from the hypothalamus through another hormone called thyrotropin-releasing hormone (TRH).

Once there is TSH in the blood, it contacts cells in the thyroid gland to produce two more hormones:

• T3 or triiodothyronine. This is much more active than T4 and it is the one that exerts effect on the tissue. That is, it regulates their metabolism.
• T4 or thyroxine. This has minimal effect on the tissue. It is closer to a kind of reserve for T3. Because when T4 reaches the tissue, it can be converted to T3, which is the hormone that performs the final action.

T3 and T4 seek out the tissue to control the conversion of proteins, carbohydrates and fats. In addition  , these are very important for babies as they contribute to the normal development of a newborn’s brain tissue.

The thyroid gland is stimulated by TSH, which in turn is dependent on TRH.

Why does the concentration of thyroid-stimulating hormone in the blood decrease?

According to a study published in 2017, which included about 4,550 people aged 18 to 93 years, the prevalence of hypothyroidism was 9.1%. In comparison, the prevalence of hyperthyroidism was 0.8%.

Together, these two disorders affect 10% of the population and it would be possible to find an abnormal TSH result in all these patients. The hormone we are talking about regulates in three ways:

• The amount of TRH released from the hypothalamus.
• The pituitary gland, which is responsible for storing and secreting TSH when required.
• Negative feedback from thyroid hormones.

What is negative feedback?

Their number in the blood increases when the production of thyroid hormones is high. The hypothalamus and pituitary gland both detect this increase, and decrease their production of TRH and TSH. This is what is meant by negative feedback.

That is, the hormones regulate themselves, to create stable levels in the blood. We would constantly swing between hyperthyroidism and hypothyroidism without this mechanism.

THS levels in the blood

The normal level of TSH in the blood is between 0.4 and 4 mE / l. This is a malfunction of the thyroid gland if the level is higher or lower.

In particular, a low TSH shows that there is so much T3 and T4 in the blood that it creates a negative feedback to the pituitary gland, thus stopping production. This is what is usually called hyperthyroidism.

There is also low TSH due to secondary hypothyroidism, and it occurs when a failure of the pituitary gland occurs, either because part of it has been destroyed or something prevents it from functioning properly – such as a brain tumor.

As the latter, tertiary hypothyroidism may be the culprit. This means that the hypothalamus does not work and stops forming TRH. Therefore, it does not send a signal to the pituitary gland to form TSH.

In the first case, where there is an overproduction of the peripheral hormones of the thyroid gland, there will be high concentrations of T3 and T4 in the blood. This indicates that the metabolism is working too hard. Therefore, the body will start burning all the fats and sugars in the body to provide energy.

Treatment of imbalances in the thyroid stimulating hormone

Hyperthyroidism

Some of the symptoms of hyperthyroidism are nervousness, palpitations, hyperactivity and increased sweating. Hypersensitivity to heat, increased appetite and weight loss are also seen.

Talk to your doctor if you suspect you have hyperthyroidism. Your doctor should be able to do blood tests that can check your concentration of TSH, T3 and T4. Hyperthyroidism can be confirmed if the concentration of thyroid stimulating hormone is low while the number of hormones from the thyroid gland is high.

The causes can range from a tumor in the thyroid gland to an autoimmune disease in which the antibodies produced overstimulate the cells in the thyroid gland. There are medications that can relieve and control all symptoms.

In general, hyperthyroidism increases heart rate and metabolism, leading to weight loss.

Hypothyroidism

Symptoms that are in contrast to the above, such as fatigue, weight gain, coldness and low body temperature, may point to hypothyroidism. This may be because you have a brain tumor that destroys the pituitary gland or compresses it, preventing the secretion of TSH. It can also be due to a low production of T3 and T4 in the gland itself.

Low TSH associated with hypothyroidism suggests a serious problem – one associated with degradation of the pituitary gland. And conversely, if TSH is normal or high, the thyroid gland may be to blame.

Thanks for reading.