Why do people develop hypothyroidism, what are the signs and symptoms, and how is this condition treated? This overview should equip you with the basic facts.

An underactive thyroid — hypothyroidism — is a disorder of the thyroid gland in which the gland fails to produce enough thyroid hormone. This condition can lead to a number of symptoms like fatigue, weight gain, poor ability to tolerate cold, constipation, skin problems, pregnancy complications, and even depression.

What you need to know about thyroid health

According to the American Thyroid Association, more than 12 percent of the US population will develop either an underactive or overactive thyroid at some point during their lifetime. Approximately 20 million US citizens have a thyroid condition — and more than half of thyroid disease patients don’t even know they have it.

Hypothyroidism: Risk factors

Even though anyone can develop hypothyroidism at any point in life, certain groups are at a higher risk:

  • Women.
  • People with a family history of the disease.
  • People over 60 years of age.
  • People with an autoimmune disease such as Hashimoto’s disease, diabetes, and celiac disease, among others.
  • People treated with radioactive iodine.
  • Those who had thyroid gland surgery.
  • Pregnant or women who recently delivered a baby.

Causes of hypothyroidism

Autoimmune disorders

The most common cause of an underactive thyroid is an autoimmune condition called Hashimoto's thyroiditis, as well as two other autoimmune disorders – vitiligo, and type 1 diabetes. It’s unknown why people get Hashimoto’s thyroiditis, but it often occurs in combination with these two other autoimmune conditions.

Autoimmune disorders happen when a person’s immune system produces antibodies that attack the body’s own tissues.

Thyroid surgery

You should know that another reason why a person might get hypothyroidism is as a complication of thyroid gland surgery. There’s an invasive therapy for thyroid cancer or sometimes for an overactive thyroid called radioactive iodine therapy, which can damage or destroy the thyroid cells that have absorbed the radiation.

Certain medications

Certain medications can affect your thyroid gland and lead to hypothyroidism. These include lithium, commonly used to treat mental health issues such as bipolar disorder and depression. Amiordarone (Pacerone, Cordarone) is a drug commonly used in the treatment of arrhythmia and it can lead to an underactive thyroid. Medications prescribed for hepatitis C and cancer known as interferons can lead to developing underactive thyroid as well.

Less common causes of hypothyroidism

There’s a condition called congenital hypothyroidism where a baby is born with an underactive thyroid because the thyroid gland hasn’t developed properly inside the womb. This is quite uncommon and easy to detect during a routine checkup.

Sometimes a damaged pituitary gland – part of the brain that regulates the thyroid – can lead to thyroid problems. Pregnancy is also a rare cause of underactive thyroid, but women can experience inflammation of the thyroid gland during the postpartum period. This leads to sudden ups and downs in thyroid hormone levels. The majority of women regain their thyroid health after a while.

Too little iodine in your diet can cause hypothyroidism. Iodine is necessary for the body to produce enough thyroid hormone because the body doesn’t make it on its own. Iodized table salt is a good source of iodine, as well as shellfish, eggs, seaweed, and dairy products.

Signs and symptoms of hypothyroidism

Symptoms of hypothyroidism differ among people and they depend mostly on the severity of thyroid hormone deficiency. The symptoms take several years to fully develop and someone with hypothyroidism may live for years without realizing that they have issues with their thyroid. Tiredness and weight gain are among the first signs of thyroid problems, but most people attribute these to aging.

Constipation is also a common symptom of underactive thyroid. Hypothyroidism is one of the top reasons for serious digestive issues because thyroid hormone regulates motility in the gut. When a person lacks thyroid hormone, the frequency and the quality of bowel movements also change. Facial swelling and hair loss can be signs of hypothyroidism as well, although not that common.

When it comes to low thyroid in children, it can be tricky to detect because the symptoms that are characteristic of the disorder such as loss of appetite, mood changes, changes in sleep patterns, and lack of energy can also be a part of the normal growing process. It’s important to screen your child as soon as you notice that something might be wrong, because hypothyroidism is easily manageable in children if detected and treated on time.

Warning signs and symptoms of hypothyroidism appear in babies as soon as they are born and often include:

  • Jaundice
  • Decrease in appetite
  • Being more lethargic than usual
  • Tongue swelling
  • Protruding navel

It’s difficult to notice underactive thyroid immediately after the baby is born because the symptoms are quite subtle. As the child grows, they tend to become increasingly apparent.

How is hypothyroidism diagnosed?

There are a few ways to diagnose underactive thyroid, but the best and most reliable way to find out whether you have the condition is through blood tests.

Physicians usually ask for three kinds of tests when diagnosing underactive thyroid:

A serum TSH test is probably the best way to diagnose underactive thyroid because thyroxine and triidothyronine hormones are sent into the bloodstream through this hormone. This specific test measures the level of TSH hormone and if the result is raised TSH, the test is repeated after couple of weeks to confirm the result.

These tests are considered reliable as they can detect even the smallest changes in your thyroid function.

Treatment of underactive thyroid

Hypothyroidism treatment isn't straightforward, as the condition requires constant attention and drugs — probably for the rest of your life. Hormone replacement therapy is one of the best medication options for an underactive thyroid, but you have to be careful because drugs can weaken your bones and cause spikes in blood pressure. This is why more and more people with underactive thyroid choose to treat the disease in more than one way, with natural and safer options such as thyroid glands from animal sources, and natural mind-body techniques.

Levothyroxine sodium

Levothyroxine is a man-made thyroid hormone that can decrease the symptoms of hypothyroidism. Once diagnosed with underactive thyroid, chances are that you'll need to take the drug for the rest of your life. This is why it’s crucial to establish the right dosage of levothyroxine. You should never exceed the recommended dose, or you might experience issues like nausea, headaches, angina, and problems with digestion.

The average dosage of levothyroxine for adults is 1.7 micrograms per kilogram of body weight. The therapy can be conducted in healthy people younger than 50 years, and those older than 50 with no serious health issues. When it comes to children and levothyroxine, it’s important to speak to your doctor about your child’s age and other factors that play a role in deciding about the right dosage.

Certain drugs can interfere with the absorption of thyroid hormone such as anticonvulsants, drugs used to treat stomach acidity that contain magnesium hydroxine and aluminum, and some medications used to treat cancer. Also, levothyroxine can render some medications ineffective, and this is why it’s important to familiarize your physician with your entire medical history.

Combination of levothyroxine and triiodothyronine

While treatment with levothyroxine is the standard way to treat underactive thyroid, some people prefer to combine levothyroxine (T4) with triiodothyronine (T3) — another thyroid hormone, but studies haven’t proven the superiority of dual therapy over monotherapy.

Desiccated animal thyroid

Desiccated animal thyroid hormone is a replacement hormone mostly made from bovine or pig glands. Most expert endocrinologists are hesitant towards these pills because they can cause bad reactions and there’s also lack of research on their safety. Regardless of the skepticism, many hypothyroid patients don't care can still use these pills just to lose some weight and have their thyroid-stimulating hormone under control.

Should you treat subclinical hypothyroidism?

Subclinical hypothyroidism, also known as mild hypothyroidism, is a health condition where a person has increased concentration of TSH, but normal serum free thyroxine. According to data, this is a common condition, affecting about 10 percent of women over 55 years of age.

There’s a difference of opinion going on in expert circles whether subclinical hypothyroidism should be treated with hormonal therapy or not. The decision should be made only after careful consideration of all the factors such as the patient's age, symptoms, the presence of antibodies, predisposition to cardiovascular diseases, and other factors.

Hypothyroidism in pregnancy

If hypothyroidism during pregnancy is left untreated, it can lead to potentially serious complications. Women are at risk of preeclampsia, heart conditions, and even miscarriage. If your hypothyroidism is under control and you visit your doctor often, the entire pregnancy should run smoothly.

Hypothyroidism in children and adolescents

Even though hypothyroidism is most common in adults, it can strike children as well. It can be hard to recognize the symptoms of hypothyroidism in infants and young children because symptoms that are characteristic for underactive thyroid such as loss of appetite, bad sleep, and decreased energy can also be a normal part of growing up.  If a baby is born with the condition, it's called congenital hypothyroidism. Routine screenings after birth have shown that one in 1,500 to 3,000 children are born with hypothyroidism.

Alternative treatments for underactive thyroid

Many hypothyroid patients decide to turn to nature and natural practices in combination with medications. Practices such as yoga, meditation, nutritional therapy, massage, dietary supplements, as well as chiropractic treatment, homeopathy and naturopathy among other forms of therapy can help to ease the symptoms of hypothyroidism. Even though studies support the benefits of yoga for people with hypothyroidism, most physicians still refuse to acknowledge anything other than conventional medicine as a form of therapy.


Although there's no specific program or food regimen for those who suffer from underactive thyroid, most doctors recommend consuming a varied and healthy diet. To ease the symptoms of the condition, some people decide to take vitamins and other dietary supplements.

Herbs and supplements

Before you decide to take supplements for you thyroid health, you must notify your doctor about it, because sometimes, supplements can affect the absorption of certain medicines or lead to serious side effects. For a good thyroid, you can take a multivitamin with essential nutrients and minerals every day or certain vitamins and minerals that your doctor can recommend:

  • L-carnitine. Studies have found that L-carnitine can help with fatigue, especially in patients who went through thyroid cancer.
  • All vitamins in the vitamin B family are good in the management of hypothyroidism, but vitamin B2 (riboflavin), B3 (niacin), and B12 (cobalamin) are by far the best to control your underactive thyroid.
  • Zinc is crucial mineral when it comes to overall health of the entire body. Zinc can affect hypothalamus to release the signals to produce more thyroid hormone.
  • Selenium is good for your thyroid health as well. It stimulates the production of thyroid hormones and removes toxins.
  • Vitamin D is also a powerful supplement for thyroid function, as well as vitamin A, vitamin C, vitamin E and antioxidants. Therefore, the foods rich in these supplements must be consumed every day.

You should stay away from iodine supplements if you have hypothyroidism. Don't go overboard with dietary sources of iodine either, such as soy, dairy, and eggs, among other foods. If you suffer from an underactive thyroid, avoid fiber supplements as they are known to affect thyroid medications. Too much fiber in your diet can also lead to malabsorption of levothyroxine.


Exercise plays a role in managing hypothyroidism, but you shouldn’t go overboard with it and make your condition worse. Lower intensity cardio such as walking, dancing, or jogging, and basically anything that can make your heart rate go up a bit should be enough. You should do cardio at least three or four times a week, anything between 30 minutes to an hour.

Underactive thyroid affects the muscles as well, so it’s important to include strength training into your weekly routine. Make sure to train the entire body equally.

What happens if hypothyroidism is left untreated?

Low pitched and hoarse voice

People have experienced low pitched voice and hoarseness for many reasons. Underactive thyroid is one of them. If you notice that your voice is becoming raspy, and you have other symptoms mentioned above, talk to your doctor as you might have problems with your thyroid gland.


Underactive thyroid decreases body temperature which causes the body to retain fluids. This can make the face and other parts of the body puffy and swollen. If your face, ankles or eyelids often look puffy for no apparent reason, check in with your doctor.

Thinned eyebrows

Damaged and thinned hair is a common symptom of hypothyroidism. When a person lacks thyroid hormone, many hair follicles enter a resting mode at once. This occurs all over the body, not just with hairs on the head or eyebrows.

A slow heart rate

Hypothyroidism slows down the heart beat, which affects the intensity of pumping and the flexibility of blood vessels, and causes blood pressure problems. Both low and high blood pressure are connected with thyroid, but hypertension is three times more common in people with underactive thyroid.

Hearing loss

Both underactive and overactive thyroid have been linked to hearing loss. It’s still unknown why this happens. Studies have shown that those who undergo head or neck radiation therapy for thyroid cancer are likely to experience hearing loss.


Underactive thyroid is known to cause normocytic, microcytic, and macrocytic anemia. In fact, anemia is one of the first signs and symptoms of hypothyroidism.

Complications arising from untreated hypothyroidism


Goiter is a swelling in the neck area caused by underactive thyroid. Goiters develop when the body tries to stimulate the thyroid gland to make more thyroid hormones.

Heart problems

Untreated hypothyroidism increases the risk of cardiovascular disease. This is because low thyroxine levels tend to increase the amount of cholesterol in the blood. Increased levels of bad cholesterol can cause fat to build up in your arteries, restricting blood flow throughout the body.

Mental problems

Thyroid underactivity can cause mental issues such as:

  • Difficulties concentrating
  • Short-term memory loss
  • Lack of interest
  • Decreased mental alertness

Peripheral neuropathy

Peripheral neuropathy is a condition in which nerves that should transfer messages between the brain and spinal cord and the rest of the body don’t work as they should. Hypothyroidism rarely causes this, unless it’s left untreated for too long. The best way to treat this condition is with levothyroxine and healthy food.

Myxedema coma

Rarely, untreated hypothyroidism can lead to a serious and life-threatening condition called myxedema coma, where the thyroid hormone levels become extremely low, leading to confusion, hypothermia, and drowsiness. This condition requires urgent treatment in hospital. It's mostly treated with intravenous hormone replacement therapy. In some cases, a person will need additional treatments such as antibiotics, breathing support, or steroid drugs (corticosteroids).


Scientists have found a link between underactive thyroid and infertility in women. Low levels of thyroid hormone can affect the release of eggs (ovulation), which impairs a woman’s fertility.

Pregnancy complications

  • Preeclampsia – a condition which can cause hypertension in the mother and growth problems in the baby.
  • Maternal anemia
  • Hypothyroidism in the baby
  • Premature birth
  • Low birth weight
  • Birth abnormalities
  • Abnormal post-partum bleeding
  • Impairments in the physical and mental development of the baby
  • Stillbirth
  • Miscarriage
These were the most common problems that come with hypothyroidism that one should know about, and they can be avoided with the right treatment under the guidance of your general practitioner and an endocrinologist. Notify your physician if you’re trying to get pregnant so you can do all the necessary screenings, especially if you notice some of the symptoms mentioned above or suspect  having an underactive thyroid.
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