Hypothyroidism vs. Hyperthyroidism: Understanding Your Symptoms

The Symptoms of an Underactive and Overactive Thyroid

woman feeling tired
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It may seem like the symptoms of your thyroid problem—whether you are underactive (hypothyroidism) or overactive (hyperthyroidism)—are as hard to pin down as the thyroid diagnosis itself. Open any medical reference or read through any website and you will see very different, lengthy lists of the symptoms that may point to a thyroid condition.

Thyroid symptoms are also confusing because they are frequently identical to the symptoms of many other diseases and health conditions.

For example, joint aches and pains can be signs of arthritis or insufficient exercise, weight gain may be related to menopause or to overeating, and fatigue can be a sign of dozens of conditions. It's easy for you—and your doctor—to assume that your thyroid symptoms are caused by other health conditions, your age, your lifestyle, or stress.

Among reputable medical sources, however, it seems that there is some medical agreement that the following are the key symptoms differentiating hypothyroidism and hyperthyroidism.

Hypothyroidism Symptoms

An underactive thyroid—known as hypothyroidism—can have a number of symptoms that reflect a slowdown in your body's processes and metabolism. They include:

  • loss of hair from the outer edge of eyebrows
  • feeling cold, especially in your hands and feet 
  • constipation
  • muscle cramps
  • joint aches/pain
  • increased menstrual flow
  • more frequent periods
  • infertility/miscarriage
  • unusually low blood pressure
  • unusually low pulse/heart rate
  • frequent infections
  • low sex drive
  • bloating/puffiness/swelling in your hands, feet, eye area, face
  • carpal tunnel syndrome
  • tarsal tunnel syndrome
  • foot and heel pain
  • persistent tics in the eye
  • neck pain
  • sensitivity to ties, scarves
  • swelling in the neck, neck enlargement
  • sore throat
  • increased sensitivity to cold
  • hoarseness
  • muscle weakness
  • elevated cholesterol levels

These symptoms are only the tip of the iceberg. With hypothyroidism, there are many symptoms and risk factors that should be considered as part of your hypothyroidism diagnosis and treatment. It's best to have a thorough, detailed discussion with your doctor so that he or she can aid in properly diagnosing and helping you manage hypothyroidism.

Hyperthyroidism Symptoms

Hyperthyroidism differs from hypothyroidism int hat your symptoms will usually reflect an increased metabolism due to the excess thyroid hormone and a speeding up of your body’s processes.

Common hyperthyroidism symptoms include:

  • anxiety and nervousness
  • panic attacks
  • anger and irritability
  • weight loss without dieting
  • increased appetite with no weight gain
  • unrelieved hunger
  • excessive thirst
  • tremors
  • heart palpitations
  • a high pulse/heart rate
  • high blood pressure
  • your hair is finer, thinner
  • unusually smooth skin texture
  • diarrhea or loose stools
  • insomnia
  • light menstrual periods
  • lack of menstrual periods
  • heat intolerance
  • increased sweating
  • fertility problems
  • shortness of breath
  • itching and hives
  • neck pain
  • sensitivity to ties, scarves
  • swelling in the neck, neck enlargement
  • sore throat
  • bulging eyes
  • double vision
  • dry eyes, sensitivity to light

Causes of Combination Symptoms

Sometimes thyroid patients experience symptoms that seem to suggest both hypo and hyperthyroidism. Is it possible to have both?

The answer is complicated. While you should always see your doctor regarding any concerns with blood pressure, heart rate, or other symptoms, there are some important factors to consider if you have symptoms of both hypothyroidism and hyperthyroidism.

You Have Hashimoto's Thyroiditis and Graves' Disease Simultaneously

Some patients actually have both Hashimoto's and Graves' disease antibodies, which puts the thyroid into a push-pull situation where it cycles between hypothyroidism and hyperthyroidism. This is not common, but hypothyroidism patients who frequently have hyperthyroidism symptoms should ask their doctors for full antibody testing to detect the presence of both Hashimoto's thyroiditis and Graves' disease.

Your Symptoms Aren't Textbook

Everyone who has hypothyroidism doesn't follow the typical course of symptoms. For example, some hypothyroidism patients lose significant amounts of weight, and some hyperthyroid patients gain significant weight. Fatigue, depression, and anxiety are common to both conditions.

You Have Dysautonomia

Imbalances in the autonomic nervous system, known as dysautonomia, are more common in autoimmune thyroid disease. In dysautonomia, the sympathetic system—part of the autonomic nervous system that controls the body's "fight or flight" reactions—becomes dysregulated. Symptoms of dysautonomia can include anxiety attacks and rapid heartbeat, which are also common symptoms of hyperthyroidism.

You're Having a Thyroiditis Flare

Some patients who have the autoimmune condition known as Hashimoto's thyroiditis are diagnosed during a period when they are hypothyroid. But in a thyroid that is failing due to autoimmune disease, the thyroid can periodically sputter into overdrive, then back into underactivity, eventually burning itself out and slowing down over time. You can, therefore, experience symptoms of overactivity—hyperthyroidism—even while your thyroid is on its way towards permanent hypothyroidism.

At the same time, Hashimoto's can also mean that periodically, the thyroid experiences a flare-up of thyroiditis, an inflammation of your thyroid gland. Thyroiditis can be accompanied by symptoms such as heart palpitations, nervousness, anxiety, panic attacks, and insomnia—symptoms typically associated with hyperthyroidism.

A Word From Verywell

Don’t be surprised if, despite being diagnosed with either hypothyroidism or hyperthyroidism, you still find yourself with symptoms from both categories.

If you are diagnosed with dysautonomia, there are some medications to help. But it’s important to know that one of the best treatments for dysautonomia is regular physical exercise, which calms down and regulates your autonomic nervous system.

If you are diagnosed with a thyroiditis flare, severe heart-related symptoms such as palpitations or a rapid heart rate can be treated with beta-blocking drugs. If your thyroiditis is causing extreme anxiety or insomnia, a short course of anti-anxiety drugs or sleeping pills may also be prescribed.

Sources:

Braverman, L, Cooper D. Werner & Ingbar's The Thyroid, 10th Edition. WLL/Wolters Kluwer; 2012.

Garber, J, Cobin, R, Gharib, H, et. al. Clinical Practice Guidelines for Hypothyroidism in Adults: Cosponsored by the American Association of Clinical Endocrinologists and the American Thyroid Association. Endocrine Practice. Vol 18 No. 6 November/December 2012.

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