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What happens when your thyroid is out of whack?

The thyroid is a small, butterfly-shaped gland located at the base of your neck. It produces hormones that regulate your metabolism – how your body uses energy. When the thyroid is not working properly, it can cause a range of symptoms that impact your whole body.

What is the thyroid and what does it do?

The main purpose of the thyroid is to produce two key hormones: triiodothyronine (T3) and thyroxine (T4). These hormones circulate through your bloodstream and affect nearly every cell in your body. Here’s an overview of how they work:

  • Regulate metabolism – T3 and T4 control the speed of your metabolism, which is how your body converts food into energy. They influence how quickly calories are burned.
  • Impact growth and development – Thyroid hormones are important for growth and development in children and teens.
  • Influence body temperature – Thyroid hormones help regulate body temperature. Low levels can cause you to feel cold.
  • Support heart health – The right amounts of thyroid hormones support heart function.
  • Affect mood – Thyroid hormones interact with serotonin and norepinephrine, which influence emotions.
  • Support healthy muscles and strong bones – Thyroid hormones contribute to muscle maintenance and strength.

As you can see, thyroid hormones impact many critical body processes. Even small changes in T3 and T4 levels can cause big effects.

What causes thyroid problems?

There are several conditions that can arise if the thyroid produces too much hormone (hyperthyroidism) or not enough (hypothyroidism):


  • Graves’ disease – This is the most common cause of hyperthyroidism in the US. It’s an autoimmune disorder where antibodies overstimulate the thyroid.
  • Thyroid nodules – Benign growths on the thyroid can sometimes secrete excess thyroid hormone.
  • Thyroiditis – Inflammation of the thyroid may cause it to release excess hormones stored in the gland.
  • Too much iodine – Consuming too much iodine through food, supplements, or medication can overstimulate hormone production.


  • Hashimoto’s disease – This autoimmune disease damages the thyroid so it doesn’t make enough hormones.
  • Thyroid surgery – Removing part or all of the thyroid usually leads to hypothyroidism.
  • Radiation therapy – Radiation treatment for cancers of the thyroid, head, or neck can impair thyroid function.
  • Medications – Drugs like lithium and interferon alpha can prevent the thyroid from producing adequate hormones.
  • Congenital hypothyroidism – Some babies are born with an underactive or absent thyroid gland.

In some cases, the specific cause of thyroid problems is unknown. The good news is both hyperthyroidism and hypothyroidism can be managed with treatment.

Symptoms of hyperthyroidism

When too much thyroid hormone circulates in your blood, it speeds up your metabolism. Common hyperthyroidism symptoms include:

  • Unexplained weight loss
  • Rapid or irregular heartbeat
  • Increased appetite
  • Nervousness or anxiety
  • Irritability
  • Fatigue
  • Trembling hands
  • Sleep problems
  • More frequent bowel movements
  • Muscle weakness
  • Thinner skin
  • Fine, thinning hair

Signs of Graves’ disease

Graves’ disease has some unique symptoms in addition to the common hyperthyroidism ones. Look for:

  • Bulging eyes (exophthalmos)
  • Double vision
  • Red or swollen eyes

Symptoms of hypothyroidism

With lower metabolism from reduced thyroid hormones, hypothyroidism causes different symptoms. They include:

  • Fatigue
  • Weakness
  • Weight gain
  • Depression
  • Muscle cramps
  • Constipation
  • Dry skin
  • Brittle hair and nails
  • Impaired memory
  • Abnormal menstrual cycles
  • Reduced heart rate
  • Sensitivity to cold

Hypothyroid symptoms tend to develop gradually over months and years. They are often subtle initially but get worse over time.

Thyroid disease complications

Untreated thyroid disorders can eventually lead to various complications. Some potential issues include:


If your thyroid is underactive, it may enlarge and form a noticeable goiter at the front of your neck. This is the gland trying to compensate for inadequate hormone production.

Heart problems

Both too much and too little thyroid hormone can affect heart function. Issues like rapid heart rate, high blood pressure, and heart failure may develop.

Brittle bones

Untreated hypothyroidism can raise your risk of osteoporosis. Poor bone health is related to lower thyroid levels.


Thyroid disorders can disrupt normal menstrual cycles and ovulation, making it harder to conceive. Male fertility may suffer too.

Birth defects

Untreated maternal hypothyroidism can increase the chances of birth defects and intellectual disabilities in infants.

Mental health issues

The thyroid influences key brain chemicals like serotonin and dopamine. Hormone imbalances increase the likelihood of depression, anxiety, and other mental health problems.

Who is at risk for thyroid disease?

There are a few key risk factors that make people more vulnerable to developing a thyroid disorder:

  • Sex – Women are 5-8 times more likely to have thyroid problems than men.
  • Age – Thyroid issues become more common with older age.
  • Genetics – You have an elevated risk if a close family member has a thyroid disorder.
  • Pregnancy – Some women develop postpartum thyroiditis after giving birth.
  • Other conditions – Autoimmune diseases, diabetes, goiter, endometriosis, and fibromyalgia increase risk.
  • Radiation exposure – Prior radiation treatment or nuclear plant disasters can damage the thyroid.
  • Iodine deficiency – Lacking enough iodine in your diet makes thyroid problems more likely.

Pay attention to your symptoms and talk to your doctor if you are concerned. Getting early treatment maximizes your chances of preventing long-term complications.

Diagnosing thyroid disorders

If you have symptoms of a possible thyroid problem, your doctor will do a medical history and physical exam. They may notice signs like a goiter, rapid reflexes, tremor, or unusual heart rate or blood pressure.

You will also likely have one or more of these tests to confirm if and how your thyroid is malfunctioning:

Blood tests

Blood levels of T3, T4, thyroid stimulating hormone (TSH), and antibodies can indicate hyperthyroidism or hypothyroidism. Typical findings include:

  • High T3 and T4 with low TSH in hyperthyroidism
  • Low T3 and T4 with high TSH in hypothyroidism
  • Elevated thyroid antibodies in autoimmune thyroid disease

Radioactive iodine uptake test

You take a small dose of radioactive iodine by mouth. Uptake levels measured hours later show how well your thyroid is functioning.

Thyroid scan

This imaging test uses a radioactive tracer to create a color-coded picture of your thyroid. It helps identify any abnormalities in the gland.


An ultrasound uses sound waves to check for thyroid nodules, tumors, cysts, or inflammation that may be causing problems.

Thyroid biopsy

If a worrisome lump or lesion is found, your doctor may withdrawn a tissue sample for examination under a microscope.

Once testing pinpoints the nature of your thyroid dysfunction, appropriate treatment can begin.

Treating hypothyroidism

Doctors typically prescribe synthetic thyroxine pills to restore normal hormone levels for hypothyroidism. This oral medication replaces what your thyroid can no longer produce. The synthetic form is identical to natural thyroxine (T4).

Brand names of this medication include Synthroid, Levothroid, Levoxyl, and Tirosint. Most people start at a low dose that is gradually increased over weeks and months. The goal is to normalize TSH blood levels.

It may take some trial and error to determine your optimal dosage. Your doctor will monitor your blood tests closely to ensure adequate treatment without over-medicating.

Tips for taking thyroxine:

  • Take it first thing in the morning on an empty stomach.
  • Wait at least 30 minutes before eating or drinking coffee.
  • Don’t take calcium, iron, prenatal vitamins, or antacids near the same time.
  • Allow 4 hours between thyroxine and these other medications or supplements.
  • Inform your doctor about all medications and supplements you take.
  • Notify your doctor if symptoms persist despite treatment.

With the right thyroxine dosage, most people with hypothyroidism can avoid complications and feel completely normal. You will likely need to remain on medication for life.

Treating hypothyroidism during pregnancy

Expecting mothers need thyroxine dose adjustments during pregnancy. Your thyroid requirements increase to support you and the developing baby. Your doctor will closely monitor your thyroid levels each trimester to prevent problems.

Treating hypothyroidism in infants and children

All newborns in the United States are screened for hypothyroidism. Treatment needs to begin right away to prevent intellectual disability and growth failure. Infants are given thyroxine drops or tablets based on their weight.

For children on growth hormone therapy, thyroid levels must be carefully regulated to maximize treatment effectiveness.

Treating hyperthyroidism

Hyperthyroidism has three main treatment options:

  1. Antithyroid medications – Drugs like methimazole (Tapazole) and propylthiouracil (PTU) block thyroid hormone production. They are a common choice for pregnant women, children, teens, and adults with mild cases.
  2. Radioactive iodine – Swallowing a radioactive iodine capsule destroys overactive thyroid cells and restores normal function. It is the standard treatment for most adults, but not used in pregnancy.
  3. Surgery – Removing part or all of the thyroid gland is sometimes done for large goiters or nodules. Full thyroidectomy leads to hypothyroidism requiring lifelong medication.

The option that is best for you depends on the cause of your hyperthyroidism, other medical conditions, and your doctor’s recommendation.

Treating Graves’ disease

Graves’ disease often goes into remission after 6-18 months of antithyroid drugs. Radioactive iodine or thyroidectomy may be alternatives if medications are intolerable or ineffective.

Eye symptoms like bulging and double vision are treated separately with steroid eye drops, protective glasses, and surgery if needed. Close coordination with an ophthalmologist is important.

Managing hyperthyroidism during pregnancy

Methimazole or PTU are the preferred treatments for expectant mothers since radioactive iodine and surgery can harm the fetus. The lowest effective dose is used. Thyroid levels require close monitoring throughout pregnancy.

Thyroid disorder diet tips

While medication is the foundation of treatment, your diet can also make a difference in thyroid disease management. Here are some nutrition tips:

Avoid potential goitrogens

Goitrogens are substances that may interfere with iodine absorption and thyroid function. Limit intake of raw cruciferous veggies, soy, millet, peanuts, and certain other foods if you have thyroid problems.

Eliminate added sugars and refined carbs

A diet high in sugary and processed foods tends to worsen many thyroid symptoms. Focus on lean proteins, fruits, vegetables, and whole grains instead.

Increase selenium

Selenium deficiency can contribute to autoimmune thyroid disease. Good sources include Brazil nuts, eggs, liver, tuna, cod, and sunflower seeds.

Use iodized salt

Getting sufficient dietary iodine from table salt, seafood, eggs, dairy, and fortified grains may help prevent thyroid problems.

Treat other nutrient deficiencies

Work with a dietitian to identify and address any nutritional shortfalls in iron, vitamin D, B12, or other vitamins and minerals that may exacerbate thyroid symptoms.

Outlook for thyroid patients

The prognosis for hypothyroidism and hyperthyroidism is generally excellent with appropriate treatment and follow-up care. Symptoms improve, complications are prevented, and most people can expect normal lifespan.

However, lifelong medication is required in most cases. Ongoing medical monitoring, blood tests, and medication adjustments will be necessary. Excellent symptom control requires your partnership with the healthcare team.

Let your doctors know about any medications, nutritional supplements, or lifestyle changes. Report any persistent or concerning symptoms. Being closely involved in your care helps ensure optimal thyroid function.


Thyroid problems affect metabolism, energy, weight, mood, and essentially every cell in the body. Both hypothyroidism and hyperthyroidism have a range of possible causes.

Symptoms may develop gradually but can be vague and easily missed in early stages. Typical signs include fatigue, weight changes, skin and hair changes, body temperature sensitivity, bowel issues, heart palpitations, muscle weakness, and menstrual cycle abnormalities.

Blood tests help diagnose thyroid dysfunction. Medication to restore normal hormone levels is the typical treatment. Lifestyle measures like a goitrogen-limited, nutrient-rich diet can also help.

Close monitoring and follow-up care are important for both hypothyroidism and hyperthyroidism. But with proper treatment, most people with thyroid disorders can expect to lead normal, active lives.