What causes thyroid symptoms? Related conditions and treatments

Medically reviewed by Anne JacobsonMD, MPH
Board-Certified Family Physician
Updated Mar. 27, 2024  •  Published Feb. 27, 2023
Fact Checked
Thyroid symptoms

Overview of thyroid symptoms

The thyroid produces hormones that affect every part of the body. When the thyroid secretes too much hormone, it’s called overactive thyroid or hyperthyroidism. Symptoms of hyperthyroidism can include feeling nervous or restless, a fast or irregular heartbeat, trouble sleeping, diarrhea, weight loss, weakness, and feeling hot. Some people will experience hand tremors or note changes in the menstrual cycle.

When there is too little thyroid hormone, it’s called underactive thyroid or hypothyroidism. People with hypothyroidism may feel sluggish, tired, or depressed. Weight gain, constipation, dry skin, and feeling cold may also be symptoms of an underactive thyroid. Hypothyroidism can also cause changes in the menstrual cycle.

At first, people often don’t realize that it’s the thyroid causing their symptoms. Many cases of hypothyroidism and hyperthyroidism are subclinical in the beginning, meaning that symptoms are very mild and hard to detect. Sometimes another diagnosis is made before the thyroid is checked. 

RELATED: Hypothyroidism vs. hyperthyroidism

Key takeaways:

  • Thyroid symptoms may be caused by a variety of health conditions, or as a side effect of medications or other medical treatments.

  • Thyroid symptoms usually improve when the underlying condition is treated. 

  • Hypothyroidism is treated with medications such as levothyroxine. Hyperthyroidism is treated with procedures or medications such as methimazole and propylthiouracil.

  • Save on prescriptions for thyroid conditions with a SingleCare prescription discount card.

What causes thyroid symptoms?

The most common cause of hypothyroidism is:

  • Hashimoto’s disease, an autoimmune disorder in which the immune system attacks healthy tissues in the thyroid

 Other causes of an underactive thyroid include:

  • Thyroid surgery

  • Radiation treatment to the neck, head, or brain

  • Radioactive iodine treatment

  • Being born with an underactive thyroid (congenital hypothyroidism)

  • Side effect of some prescription drugs (including amiodarone, interferon-alpha, nivolumab, pembrolizumab, alemtuzumab, and lithium)

  • Some types of thyroid cancer

  • Not enough hormone produced by the pituitary gland in the brain

  • Changes during or after pregnancy 

  • Thyroid swelling (thyroiditis)

  • Not getting enough iodine in the diet

The most common causes of hyperthyroidism are:

  • Graves disease, an autoimmune disease in which antibodies stimulate over-secretion of thyroid hormone 

  • Enlargement of the thyroid with multiple thyroid nodules (multinodular goiter)

  • A single, overactive thyroid nodule

  • Inflammation of the thyroid

Other causes of hyperthyroidism include:

RELATED: How does COVID-19 affect the thyroid?

Should I be worried about thyroid symptoms?

See a healthcare provider if you experience symptoms of an underactive or overactive thyroid. Untreated thyroid problems can lead to long-term complications, or could even cause a medical crisis. 

Untreated hypothyroidism can lead to mental health problems, long-term thyroid enlargement, chronic pain, high cholesterol, and swelling. Even mild hypothyroidism

creates a higher risk for cardiovascular disease, stroke, heart failure, and cognitive decline. In children and adolescents, hypothyroidism can delay growth and development. In older adults, confusion or memory problems may be symptoms of a thyroid problem.

Severe hypothyroidism is called myxedema. It is a potentially fatal medical emergency. Any of the causes of low levels of thyroid hormone can lead to myxedema. Get immediate medical attention for symptoms of:

  • Altered mental status

  • Low body temperature

  • Slow breathing

  • Dry skin

  • Hair loss

  • Slow reflexes

  • Slow heart rate

  • Low blood pressure

  • Puffy face

  • Lethargy

  • Coma 

High levels of thyroid hormone are equally serious. Hyperthyroidism could escalate into a “thyroid storm” if thyroid hormones rise to dangerous levels. A thyroid storm is a time-critical medical emergency. It can be life-threatening and lead to heart failure, dangerous heart rhythms, and liver failure. Get emergency medical care for symptoms of:

  • Extreme anxiety or panic

  • Confusion, delirium, or other changes in mental status

  • High fever

  • Diarrhea

  • Very fast heartbeats or heart flutters

  • Loss of consciousness

  • Symptoms of heart failure such as swelling of the legs, shortness of breath, fatigue, and weakness

  • Symptoms of liver dysfunction like yellow skin, yellow eyes, or abdominal pain

Untreated hyperthyroidism from Graves disease may lead to eye problems such as double vision or bulging eyes.

How are thyroid symptoms diagnosed?

 A healthcare professional will perform a physical exam, medical history, and a blood test. The first blood test usually measures the level of thyroid-stimulating hormone (TSH). Based on that test, additional blood tests may include T3 (triiodothyronine), T4 (thyroxine), and a check for antibodies that may be affecting the thyroid. Imaging studies, like an ultrasound or thyroid scan, may be needed to pinpoint the cause.

RELATED: How to understand thyroid panel results

How long do thyroid symptoms last?

Symptoms of hypothyroidism or hyperthyroidism usually improve once the underlying condition is treated. Some symptoms caused by severe or longstanding diseases may take longer to resolve. 

Thyroid symptoms caused by medication side effects or diet are resolved by stopping the medications or adjusting the diet. Thyroid symptoms that occur during pregnancy or after delivery may resolve on their own or need treatment for a short time. Sometimes an illness or inflammation also causes temporary thyroid problems that improve in a few weeks or months. 

But most thyroid conditions will require treatment in the form of medication, radioactive iodine treatment, or surgery.

RELATED: Understanding thyroid problems during pregnancy

Treating thyroid symptoms

Treatment of thyroid symptoms will depend on the nature of the thyroid problem. Underactive thyroid is treated with thyroid hormone pills, usually levothyroxine, Armour Thyroid, or similar prescription thyroid hormones. An overactive thyroid can be managed with drugs that block the thyroid’s production of hormones, including methimazole or propylthiouracil. Beta blockers may also be used to block the effects of too much thyroid hormone, such as a fast heart rate or tremor. Overactive thyroid may require radioactive iodine treatment or surgery to eliminate hormone-producing tissues in the thyroid. These treatments will result in permanent hypothyroidism, so thyroid hormone replacement will be required from that point on.

RELATED: What is Synthroid and what is it used for?

Living with thyroid symptoms

The best way to live with thyroid symptoms is to work with your healthcare provider to diagnose and treat your thyroid condition. 

Natural remedies for thyroid symptoms lack evidence of efficacy and safety, according to the American Thyroid Association. Taking certain supplements or medications without the guidance of a healthcare professional can even lead to thyroid symptoms. However, a lifestyle that includes a healthy diet, exercise, getting enough sleep, avoiding smoking, limiting alcohol, and managing stress can help to support a healthy hormone balance. 

Get tested 

While up to 12% of the population has thyroid disease, as many as 60% of those people don’t know they have it. Symptoms may be very mild, nonspecific, or mimic other health conditions. At best, thyroid problems interfere with daily life. At worst, they can lead to serious complications. If you have symptoms of thyroid problems, even if they’re mild, see your healthcare provider. This is especially important if you’re pregnant or planning for pregnancy, if you’re over the age of 60,  if you have an autoimmune condition, including Type 1 diabetes, or have an immediate family member with thyroid problems. Most states also require newborn screening, which includes a test for congenital hypothyroidism.

RELATED: Thyroid health 101: Common problems you should watch out for

FAQs about the causes of thyroid symptoms

What are thyroid symptoms in males?

Some men may experience breast growth (gynecomastia) or erectile dysfunction in addition to other symptoms of hypothyroidism. 

What are thyroid symptoms in females?

Both hyperthyroidism and hypothyroidism can interfere with the menstrual cycle, leading to absent or irregular periods. Additionally, women are more likely than men to have subclinical hypothyroidism, with few or mild symptoms. This condition still needs to be diagnosed and treated to prevent more serious problems in the future. For this reason, women are encouraged to get screened for thyroid dysfunction.

What are the early warning signs of thyroid problems?

The thyroid affects many different body functions, so there are no definitive early warning signs of thyroid problems. However, some of the common symptoms, even if they’re not specific, are good indicators that medical help is needed. For instance, persistent fatigue or a change in bowel habits is a good reason to talk to a healthcare provider. Other symptoms like unintended weight gain or weight loss, or heart palpitations are also convincing reasons to make a visit to your healthcare provider. 

Medically reviewed by Anne JacobsonMD, MPH
Board-Certified Family Physician

Anne Jacobson, MD, MPH, is a board-certified family physician, writer, editor, teacher, and consultant. She is a graduate of University of Wisconsin School of Medicine and Public Health, and trained at West Suburban Family Medicine in Oak Park, Illinois. She later completed a fellowship in community medicine at PCC Community Wellness and a master's in Public Health at the University of Illinois-Chicago. She lives with her family near Chicago.

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