Hypothyroidism - Causes, Symptoms, Diagnosis and Treatment

Hypothyroidism

Authored by DesiMD Doctor on 19 Mar 2013 - 18:16.

Thyroid-Functioning-System

It is estimated that 42 million people in India suffer from thyroid disease. The common thyroid disorders include hypothyroidism, hyperthyroidism, iodine deficiency, goiter disorders and thyroid cancer. Hypothyroidism is more common than other thyroid disorder. It is commonly seen among women than men. Let’s learn some basic facts about hypothyroidism here.

What is thyroid and what are the functions of thyroid hormone?
Thyroid gland is a butterfly shaped gland located in middle of the neck. It secretes the thyroid hormone that regulates the metabolism of our body. 

What is hypothyroidism?

Hypothyroidism is a condition which results from a deficiency of thyroid hormone, meaning the body does not make enough thyroid hormone.

The function of the thyroid gland is regulated by the pituitary gland.  The pituitary gland is located in the brain and produces thyroid stimulating hormone (TSH) which stimulates the production of thyroid hormone. The functioning of pituitary gland is in turn regulated by hypothalamus (another structure in the brain). Hypothyroidism can be seen when there is decreased function of the thyroid gland (primary) or decreased function of the pituitary (Central).

There are many causes of hypothyroidism, some of which are listed below:

  • Hashimoto’s thyroiditis is the most common cause. In this condition there is inflammation of the thyroid leading to destruction of the thyroid tissue.
  • Surgical removal of thyroid gland.
  • Radiation to the thyroid gland.
  • After radioactive iodine ablation for Grave’s disease.
  • Many medications, such as lithium carbonate, amiodarone, interferon alfa, interleukin 2 etc. can alter thyroid function.
  • Pituitary tumors, pituitary surgery can cause central hypothyroidism.
  • Congenital (occurring at birth) forms of hypothyroidism.
     

The symptoms are highly variable and nonspecific. So it is very difficult to diagnose hypothyroidism based on the symptoms.Some of the common symptoms are:

  • Feeling tired
  • Cold intolerance (feeling cold easily)
  • Hoarse voice
  • Constipation
  • Weight gain
  • Anemia 
  • Muscle aches, Joint pain
  • Skin is cool, pale, dry and rough
  • Elevated blood pressure
  • Elevated cholesterol
  • Bradycardia (low heart rate)
  • Slow mentation, poor memory, loss of concentration
  • In women, it can also cause menstrual problems, infertility, and miscarriage
  • Severe thyroid deficiency early in pregnancy can cause developmental problems in the child
  • Decreased libido (sexual desire), premature ejaculation and erectile dysfunction in men

Can it be life threatening?

Yes, severe hypothyroidism can cause Myxedema coma. Patients with this severe form of hypothyroidism present with decreased mental status (coma) and hypothermia (low body temperature) along with low blood pressure, low heart rate, low blood sugars and decreased breathing. Puffiness of the hands and face, a thickened nose, swollen lips and tongue can occur secondary to non-pitting edema due to abnormal deposits of mucin in the skin and other tissues (myxedema). It is a medical emergency and if left untreated has a mortality (death) rate as high as 40%.  It is rarely seen nowadays due to increased availability and use of thyroid testing.

Symptoms of subclinical Hypothyroidism

Subclinical hypothyroidism is a condition with extremely mild or no obvious symptoms. Patients have elevated TSH level with T4 and T3 levels in the normal range. There is difference of opinion in treatment of subclinical hypothyroidism with levothyroxine.

 

Your doctor might order simple blood test to diagnose hypothyroidism. Blood level of TSH the hormone that stimulates the thyroid gland is usually the first test done. Other blood tests that are done include T4 thyroid hormone level and antibody against thyroid gland (Anti-Thyroid peroxide antibody).

Pregnant mothers who have been diagnosed with hypothyroidism need to be extra cautious to avoid risks. The fetus (baby) depends on thyroid function of the mother until its own thyroid starts making own thyroid hormone, this usually happens around 12 weeks of pregnancy. Women may need higher doses of levothyroxine during pregnancy. Thyroid hormone levels are closely followed during pregnancy and adjusted.

NEVER alter the dose of your medication without speaking to your doctor. If you have a strong family history of thyroid disorder or any symptoms concerning thyroid problems, check with your doctor to see if you need to be tested.

The treatment is replacement therapy with medication levothyroxine (oral form of thyroid hormone T4). The medication should be taken once per day in the morning on an empty stomach (one hour before or two hours after eating food or other medications). A high fiber diet, calcium- or aluminum-containing antacids, and iron tablets can interfere with the absorption of levothyroxine (T4). So doctors usually recommend taking thyroid pill alone by itself and not to mix with other pills.

Your doctor usually repeats the blood test for TSH in four to six weeks after starting treatment to see if dose needs to be adjusted. The goals of treatment include bringing back the TSH and T4 to normal levels and improvement in symptoms.

*Disclaimer This is not medical advice. The content is for educational purposes only. Please contact your doctor for any health care issues.