Signs and causes of hypothyroidism

Symptoms and Causes of Underactive Thyroid – Hypothyroidism

Here we will present to you the symptoms and causes of an underactive thyroid – hypothyroidism. What is hypothyroidism, what are the signs, causes and what to do if you have hypothyroidism?

Hypothyroidism is an underactive thyroid gland. Hypothyroidism means that the thyroid gland can’t make enough thyroid hormones to keep the body running normally.

People are hypothyroid if they have too little thyroid hormone in the blood.

Common causes are autoimmune diseases, such as Hashimoto’s thyroiditis, surgical removal of the thyroid, and radiation treatment.

What Is The Thyroid Gland?

The thyroid gland is a butterfly-shaped endocrine gland that is normally located in the lower front of the neck.

The thyroid’s job is to make thyroid hormones, which are secreted into the blood and then carried to every tissue in the body.

Thyroid hormone helps the body use energy, stay warm and keep the brain, heart, muscles, and other organs working as they should.

What Are The Symptoms Of Hypothyroidism?

The symptoms begin so gradually that you and your doctor might not notice them until the condition is well advanced.

Low levels of thyroid hormone result in a slowing down of the mental and physical processes of the whole body.

Once treatment has started these symptoms will improve over time, but if not, you should talk to your doctor.

These are the most common symptoms:
  • fatigue and tiredness
  • increased awareness of the cold
  • dry and coarse skin
  • dry and thinning hair
  • a hoarse or croaky voice
  • constipation
  • muscle weakness, cramps, and aches
  • pins and needles in the fingers and hands (carpal tunnel syndrome)
  • heavier and longer periods
  • fertility problems
  • low libido
  • weight gain
  • puffy face and bags under the eyes
  • slow speech, movements, and thoughts
  • low mood or depression
  • memory problems
  • difficulty in concentration
  • slow heartbeat
  • slightly raised blood pressure
  • raised cholesterol
  • slowed growth (in children)

What Causes Hypothyroidism?

There can be many reasons why the cells in the thyroid gland can’t make enough thyroid hormone.

Here are the major causes, from the most to the least common.

Autoimmune disease. In some people’s bodies, the immune system that protects the body from invading infections can mistake thyroid gland cells and their enzymes for invaders and can attack them.

Then there aren’t enough thyroid cells and enzymes left to make enough thyroid hormone. This is more common in women than in men.

Autoimmune thyroiditis can begin suddenly or it can develop slowly over years. The most common forms are Hashimoto’s thyroiditis and atrophic thyroiditis.

 Surgical removal of part or all of the thyroid gland. Some people with thyroid nodules, thyroid cancer, or Graves’ disease need to have part or all of their thyroid removed.

If the whole thyroid is removed, people will become hypothyroid. If part of the gland is left, it may be able to make enough thyroid hormone to keep blood levels normal.

Radiation treatment. Some people with Graves’ disease, nodular goiter, or thyroid cancer are treated with radioactive iodine (I-131) to destroy their thyroid gland.

Patients with Hodgkin’s disease, lymphoma, or cancers of the head or neck are treated with radiation.

All these patients can lose part or all of their thyroid function.

Congenital hypothyroidism (hypothyroidism that a baby is born with). A few babies are born without a thyroid or with only a partly formed one.

A few have part or all of their thyroid in the wrong place (ectopic thyroid). In some babies, the thyroid cells or their enzymes don’t work right.

Thyroiditis. Thyroiditis is an inflammation of the thyroid gland, usually caused by an autoimmune attack or by a viral infection.

Thyroiditis can make the thyroid dump its whole supply of stored thyroid hormone into the blood at once, causing brief hyperthyroidism (too much thyroid activity); then the thyroid becomes underactive.

Medicines. Medicines such as amiodarone, lithium, interferon-alpha, and interleukin-2 can prevent the thyroid gland from being able to make hormones normally.

These drugs are most likely to trigger hypothyroidism in patients who have a genetic tendency to autoimmune thyroid disease.

Too much or too little iodine. The thyroid gland must have iodine to make thyroid hormone.

Iodine comes into the body in food and travels through the blood to the thyroid. Keeping thyroid hormone production in balance requires the right amount of iodine.

Taking in too much iodine can cause or worsen hypothyroidism.

Damage to the pituitary gland. The pituitary, the “master gland,” tells the thyroid how much hormone to make.

When the pituitary is damaged by a tumor, radiation, or surgery, it may no longer be able to give the thyroid instructions, and the thyroid may stop making enough hormones.

Rare disorders that infiltrate the thyroid. In a few people, diseases deposit abnormal substances in the thyroid and impair its ability to function.

For example, amyloidosis can deposit amyloid protein, sarcoidosis can deposit granulomas, and hemochromatosis can deposit iron.

How is hypothyroidism diagnosed?

By a physical examination and blood tests.

A thyroid function blood test is a simple and accurate way to check whether your thyroid gland is working properly.

An underactive thyroid is typically associated with a thyroid-stimulating hormone (TSH) level above the reference range and a thyroxine (FT4) level that is below the reference range.

It is reasonable to have a test for thyroid antibodies to confirm that the cause is autoimmune. Other factors such as common illnesses that can temporarily alter blood test readings will need to be ruled out.

Some medicines – prescribed and over-the-counter – can affect results, so it is important to tell your doctor about any medication you are taking.

Treatment For Hypothyroidism


Hypothyroidism can’t be cured.

But in almost every patient, hypothyroidism can be completely controlled.

It is treated by replacing the amount of hormone that your thyroid can no longer make, to bring your T4 and TSH levels back to normal levels.

So even if your thyroid gland can’t work right, T4 replacement can restore your body’s thyroid hormone levels and your body’s function. Synthetic thyroxine pills contain hormones exactly like the T4 that the thyroid gland itself makes.

All hypothyroid patients except those with severe myxedema (life-threatening hypothyroidism) can be treated as outpatients, not having to be admitted to the hospital.

For the few patients who do not feel completely normal taking a synthetic preparation of T4 alone, the addition of T3 (Cytomel®) may be of benefit.

Side Effects And Complications

Several complications can occur if you have an underactive thyroid that is not treated.
Heart problems

If you have an untreated underactive thyroid, your risk of developing cardiovascular disease is increased.

This is because having low levels of the hormone thyroxine can lead to increased levels of cholesterol in your blood.

High cholesterol can cause fatty deposits to build up in your arteries, restricting the flow of blood.


A goiter is an abnormal swelling of the thyroid gland that causes a lump to form in the throat.

Goitres can develop in people with an underactive thyroid when the body tries to stimulate the thyroid to produce more thyroid hormones.

Pregnancy complications

If an underactive thyroid is not treated during pregnancy, there’s a risk of problems occurring. These include:

  • pre-eclampsia – which can cause high blood pressure and fluid retention in the mother and growth problems in the baby
  • anemia in the mother
  • an underactive thyroid in the baby
  • birth defects
  • bleeding after birth
  • problems with the baby’s physical and mental development
  • premature birth or a low birth weight
  • stillbirth or miscarriage
Myxoedema coma

In very rare cases, a severely underactive thyroid may lead to a life-threatening condition called myxoedema coma.

This is where the thyroid hormone levels become very low, causing symptoms such as confusion, hypothermia, and drowsiness.

Myxoedema coma requires emergency treatment in the hospital.

It’s usually treated with thyroid hormone replacement medication given directly into a vein. In some cases, other treatments such as breathing support, antibiotics and steroid medication (corticosteroids) are also required.

Read More: What To Eat and What To Avoid for Hypothyroidism 

Conclusion: If you notice some of these symptoms for hypothyroidism mentioned above in text we recommend you to inform your doctor.

Medical tests and will show you if you have a problem with an underactive thyroid and what actions to take to make this problem go away.


Symptoms and causes of hypothyroidism

Symptoms of underactive thyroid

Similar Posts