Hashimoto's Hypothyroidism

All About Hashimoto’s Hypothyroidism

Hypothyroidism is an increasingly common disease; it comes in various forms but they’re all characterised by abnormally low levels of thyroid hormones T4 and T3.  There are also various causes but the most common cause globally is still iodine deficiency simply because a huge number of people with the condition live in countries where health policies addressing iodine deficiency do not exist.  In most developed countries iodine deficiencies have been resolved through initiatives like iodized salt and adding iodine to certain staple food products, like dairy and even bread.  In these countries Hashimoto’s hypothyroidism is now the single most common type of hypothyroidism.

Hashimoto’s hypothyroidism is also known as Hashimoto’s thyroiditis or Hashimoto’s disease.  It gets its name from Dr. Hakaru Hashimoto, the Japanese doctor who first described this thyroid disorder that would eventually bear his name.

Hashimoto’s Hypothyroidism – An Autoimmune Disease

Hashimoto’s hypothyroidism is classed as an autoimmune disease.  In an autoimmune disease your immune system begins to attack your body’s own cells.  There is a very complex cellular process by which this happens that is beyond the scope of this article.  Essentially though when you have Hashimoto’s disease your immune system attacks your thyroid gland and the resulting inflammation in the thyroid causes it to reduce, or stop, producing thyroid hormones.  Exactly what triggers your immune system to develop thyroid self anti-bodies (anti-bodies that attack the body’s own tissue) is not known.  It may be caused by a bacterium or a virus, or it could be predominantly genetic.

Who Commonly Gets Hashimoto’s Hypothyroidism?

Whilst all age groups and both males and females can get it, Hashimoto’s hypothyroidism most commonly occurs in middle-aged women.  If you also have a family history of thyroid disease your chances of developing it increase too.  Apart from this, people who have other autoimmune diseases are at higher risk of developing Hashimoto’s disease, particularly those with rheumatoid arthritis, lupus or type 1 diabetes.  Exposure to excessive amounts of radiation has also been linked to increased cases of Hashimoto’s.

Interesting Questions about Thyroid:

What Are the Main Types of Thyroiditis?

Chronic thyroiditis

Called Hashimoto’s thyroiditis, it is by far the most common form. It begins so slowly that most people don’t know anything is wrong. Over time, the disease destroys thyroid tissue until permanent hypothyroidism results. Some patients with Hashimoto’s have normal thyroid functions (euthyroidism) with a goiter.

Subacute thyroiditis

It’s a less common form, with far fewer cases than in chronic thyroiditis. Often caused by a viral infection, the disease lasts for several months. Subacute thyroiditis is painful, causing a tender, swollen thyroid gland with pain throughout the neck. The pain usually responds to treatment with aspirin or other anti-inflammatory drugs. At first, gland destruction causes the release of stored thyroid hormones, inducing temporary hyperthyroidism. A month or two later, the patient may become hypothyroid, because the thyroid has been damaged and its hormone reserves used up. Most patients return to normal within six to nine months, but the hypothyroidism could be permanent.

Painless thyroiditis

It causes a painless swelling of the thyroid gland. When this disease occurs after pregnancy, it is called postpartum thyroiditis. The course of painless thyroiditis is otherwise similiar to painful subacute thyroiditis.

Acute thyroiditis

A rare disease, is caused by an acute infection. Patients with the disease become very sick and have a high fever. The neck is red, hot, and very tender. Acute thyroiditis is a medical emergency and must be treated with antibiotics and surgery.

What Are the Signs and Symptoms of Thyroiditis?

Thyroiditis can cause either hyperthyroidism or hypothyroidism, or one followed by the other.

Common signs and symptoms of hyperthyroidism include:

  • fast heart rate (100-120 beats per minute, or higher)
  • nervousness or irritability
  • increased perspiration
  • muscle weakness (especially in the shoulders, hips, and thighs)
  • trembling hands
  • weight loss, in spite of a good appetite.

Common signs and symptoms of hypothyroidism include:

  • slow heart rate (less than 70 beats per minute)
  • feel slow or tired
  • drowsy during the day, even after sleeping all night
  • poor memory
  • difficulty concentrating
  • muscle cramps, numb arms and legs
  • weight gain
  • constipation
  • heavy menstrual flow.
Pregnancy & Thyroid Disease

Why are women more likely to get thyroid disease?

In general, women are much more likely than men to become hyperthyroid or hypothyroid and to get Hashimoto’s thyroiditis. The reason for this is uncertain.

Women are also more vulnerable to autoimmune diseases. Two of the most common thyroid diseases, Hashimoto’s thyroiditis and Graves’ disease, are caused by problems with the body’s immune system. Normally, the immune system defends the body against germs and viruses. In autoimmune diseases, the system attacks the body’s own tissues. Diseases of the immune system tend to run in families.

What about thyroid disease and pregnancy?

Hyperthyroidism or hypothyroidism can affect a woman’s ability to become pregnant. They may also cause a miscarriage if they are not quickly recognized and properly treated.

Women who become pregnant may not notice signs of thyroid disease because similar symptoms can occur in a normal pregnancy. For example, patients may feel warm, tired, nervous, or shaky. In addition, enlargement of the thyroid (goiter) commonly occurs during pregnancy.

A pregnant woman is treated differently than is a non-pregnant woman or a man. For example, radioactive materials commonly used in diagnosing and treating many thyroid diseases are never used in pregnant women. The timing of a biopsy or surgery for a thyroid nodule and the choice of drugs for hyperthyroidism may be different in a pregnant woman. These issues require careful consultation with your doctor.

What is postpartum thyroiditis?

Postpartum thyroiditis is a temporary form of thyroiditis. It occurs in 5%-9% of women soon after giving birth (postpartum period). The effects are usually mild. However, the disease may recur with future pregnancies.

The symptoms usually last for six to nine months. First, the damaged thyroid gland may release its stored thyroid hormones into the blood, causing hyperthyroidism. During this time, you can develop a goiter, have a fast heart rate, and feel warm or anxious. Then, a few months later, you will either return to normal or become hypothyroid. Hypothyroidism occurs because the thyroid has been damaged and its hormone reserves used up. If this happens, you may feel tired, weak, or cold. The hypothyroidism usually lasts a few months until the thyroid gland completely recovers. Occasionally, the hypothyroidism may be permanent.

How do doctors test for thyroid disease during pregnancy?

As with any disease, it is important that you watch for the early warning signs of thyroid disease. However, only your doctor can tell for sure whether or not you have the disease. Your doctor may examine:

  • your history and physical appearance
  • the amount of thyroid hormones, thyroid stimulating hormone (TSH), and thyroid antibodies in your blood.

How is thyroid disease treated during pregnancy?

Pregnancy places some limits on the treatments which you can receive, because your doctor must also look out for the safety of your child. A common treatment for hyperthyroidism is radioactive iodine, but it must be avoided by women who are pregnant or nursing a baby. Surgery to remove a goiter or cancer may also be delayed until after the pregnancy. However, needle aspiration biopsy of a thyroid nodule may be safely done during pregnancy.

Treatments which may be used for thyroid disease during pregnancy include:

  • antithyroid drugs, which block the production of thyroid hormone
  • thyroid hormone pills, which provide the body with the right amount of thyroid hormone when the gland is not able to produce enough by itself.

Postpartum thyroiditis may or may not be treated during the hyperthyroid stage, depending upon its severity. If the patient later becomes hypothyroid, her doctor may prescribe thyroid hormone pills.

Have more questions? Need more answers? Check our Full Thyroid FAQ

Hashimoto’s Hypothyroidism Symptoms

As is the case with most symptoms of thyroid disease, they’re slow to develop and often mistaken for other disorders with similar symptoms.  Due to its predominance in post menopausal women, many of the symptoms can easily be mistaken for that too and overlooked accordingly.  Sometimes someone with Hashimoto’s disease may develop goiter, which is when the thyroid swells.  As the disease progresses, symptoms worsen and it’s at this point that many people begin to realise they could have thyroid problems.

The symptoms of Hashimoto’s disease are typical of hypothyroidism and include:

  • Depression
  • Constipation
  • Tiredness
  • Sluggishness
  • Intolerance for cold
  • Dry, pale skin
  • Weight gain
  • Puffiness around the eyelids and nose
  • Alopecia (hair loss)
  • Swollen tongue
  • Brittle nails
  • Sore stiff muscles and muscle weakness
  • Pain and stiffness in joints
  • Menorrhagia or, less commonly, amenorrhea
  • Memory fog and lapses

If you do notice yourself developing any of these problems consistently you should see your doctor.  Of the most concern are unexplained and ongoing tiredness, excessively dry skin, a pale puffy face and constipation.  Any of these warrant investigating to determine their cause.

Other factors that result in the need for continual monitoring of thyroid function include:

  • previous thyroid surgery
  • radioactive iodine treatment
  • radiation therapy to the upper torso
  • anti-thyroid medications

Potential Complications Of Untreated Hashimoto’s Hypothyroidism

As is the case with all types of hypothyroidism, lack of treatment will not only lead to a worsening of symptoms but will also cause severe health problems as the disease progresses.

  • Goiter – eventually your thyroid may swell under the pressure of constantly being stimulated to produce thyroid hormones.  Enlarged thyroids may make swallowing and breathing difficult
  • Heart disease, an enlarged heart and potentially heart failure – thyroid hormones help regulate blood levels of low-density lipoprotein cholesterol (LDLs).  A drop in these hormones is often linked to a rise in LDLs
  • Increasing depression causing a decline in mental health and well-being
  • Sluggish mental functions and memory loss
  • Decreased libido
  • Myxedema and potentially myxedema coma, which is often fatal.

It’s also known that babies born to women with untreated Hashimoto’s hypothyroidism are at higher risk of having birth defects as well as brain, heart and kidney disorders.  These children also often end up with developmental and intellectual problems.