20 Subtle Signs of a Thyroid Problem Hiding in Plain Sight

Be careful not to miss these subtle but serious symptoms of a potential thyroid issue.

Your thyroid might be small, but it's also quite mighty when it comes to your overall health. The butterfly-shaped gland, located at the base of the neck, produces hormones that regulate almost all of your bodily functions. So when your thyroid isn't functioning properly, things tend to go haywire. Whether your body is producing too much thyroid hormone (hyperthyroidism) or too little (hypothyroidism), both scenarios can cause problems, impacting everything from your sleep schedule to your skin. But these subtle signs of a thyroid problem can easily go unnoticed.

Though thyroid disease is hardly uncommon—an estimated 20 million Americans have some form of thyroid disease, according to the American Thyroid Association—up to 60 percent are unaware of their condition. Keep reading to learn all about the subtle signs of a thyroid problem and be sure to see an endocrinologist if you think your thyroid might be out of whack.

Brittle nails

Closeup of chipped nails

Believe it or not, thyroid issues can manifest in your nails. The American Academy of Dermatology (AAD) says that "thick, dry, and brittle [nails]" can be a sign of thyroid disease, as can curved nails and thickening skin above the nails.

Dry skin

woman putting on lotion

Just like your nails, your skin can also become increasingly dry as a result of your thyroid not functioning properly. "If your thyroid gland is underperforming, your metabolism is slowed down. This, in turn, can reduce the skin's ability to sweat and secrete natural moisturizers, leading to dry, flaky skin," explains board-certified family medicine physician Kristamarie Collman, MD.

Poor concentration

Man looking around distracted at work

"Decreased levels of concentration may indicate an issue with the thyroid gland," says Collman. Specifically, this is a symptom that occurs in patients with hypothyroidism, and the British Thyroid Foundation notes that it is often accompanied by memory issues and increased apathy.


Asian Man Sitting at His Desk at Work Yawning {Allergy Symptoms}

Feelings of fatigue or tiredness are normal to experience on a daily basis, so it's easy to overlook them as potential symptoms of serious health conditions. However, it's also one of the hallmark signs of hypothyroidism, with Collman pointing out that "experiencing fatigue or feeling sluggish may indicate an issue with the thyroid gland."

Difficulty sleeping

Woman having trouble sleeping at night with insomnia

Are you having trouble falling asleep at night? If so, you could have an overactive thyroid. According to the National Sleep Foundation, excess thyroid hormone makes everything speed up inside your body, thereby leaving you feeling wired when you want to fall asleep.

Digestive issues

EZ Load Toilet Paper Holder

A thyroid not functioning like it should can cause digestive problems like constipation and diarrhea—it all depends on whether it is producing too much or too little of the hormone thyroxine (T4). "Constipation is one of the first signs the body may be slowing down due to hypothyroidism," explains thyroid expert Nicole German Morgan, RDN. Meanwhile, Cedars-Sinai Medical Center in California points out that diarrhea or having more bowel movements than usual are signs of an overactive thyroid.

Heat intolerance

Young white man sweating through shirt

Morgan also cites heat intolerance as a sign of hyperthyroidism. Though this uncomfortable symptom can also be caused by everything from excess caffeine intake to menopause, it's worth having your doctor check your thyroid if you're feeling overheated more often than normal.

Cold intolerance

Woman shivering under a blanket because she is so cold

While hyperthyroidism can cause you to feel excessively hot, hypothyroidism can have the opposite effect, causing you to experience an abnormal sensitivity to cold temperatures. "Slowed-down cells burn less energy, so the body produces less heat," note the experts at Harvard Medical School. "You may feel chilly even when others around you are comfortable."

Hair loss

man controls hair loss and unhappy gazing at you in the mirror

While people experience hair loss for a variety of reasons, it is one of the signs of a potential thyroid disorder. "This may occur as a result of the nutrient deficiencies like iron deficiency and vitamin B deficiency that are common in all thyroid conditions," Morgan explains.

According to the British Thyroid Foundation, hair loss caused by a thyroid disorder usually "involves the entire scalp rather than discrete areas," though it tends to improve with treatment.

Heart palpitations

woman clutching her heart

When there is too much thyroid hormone in the body, it tends to function in overdrive. As such, "a hyperthyroid patient can develop a racing heart rate and markedly elevated blood pressure that, if left untreated, could cause serious complications like heart attack, stroke, and blindness," explains Jason Cohen, MD, a surgical oncologist and thyroid specialist at Surgery Group of LA.


Shot of a mature man looking thoughtful and sad outdoors

According to psychiatrist Jared Heathman, MD, since "hormones are required to be in balance for our brains to function optimally, clinical depression can be a symptom of hypothyroidism." One 2018 meta-analysis published in JAMA Psychiatry estimates that approximately 45.5 percent of depressive disorders are associated with thyroid disease.


Shot of a senior woman suffering from stress at home

Heathman says thyroid disorders can also present as anxiety. The same meta-analysis in JAMA Psychiatry found that approximately 29.8 percent of anxiety disorders are associated with some sort of thyroid issue.


Woman on a laptop looking stressed and angry

Since your thyroid can cause depression and anxiety when it's not functioning properly, it's probably no surprise that it can lead to other mood changes, too. The American Thyroid Association notes that some of the emotional symptoms of hyperthyroidism include irritability and nervousness. So if you feel angry all the time and you don't know why, consider getting your thyroid levels checked.

Irregular periods

Woman holding a tampon

"Thyroid hormone helps to control the other hormones in the body that regulate the menstrual cycle," notes Morgan. So having either too little or too much thyroid hormone can make your periods irregular, or even cause you to skip them altogether.

Weight loss

Woman getting weighed on a scale at the doctor's office

Thyroid hormones thyroxine (T4) and triiodothyronine (T3) both play critical roles in metabolic function. Therefore, people with hyperthyroidism—who are producing too much T4 and T3—tend to experience unhealthy and unplanned weight loss as well as an increase in appetite.

Weight gain

Man trying to fasten his jeans that don't fit because of weight gain

And on the other end of the spectrum, people with hypothyroidism—when the thyroid gland doesn't produce an adequate amount of the T4 and T3 hormones—often deal with weight gain as a symptom of their condition.

Decreased libido

Divorce and separation. Black millennial couple in bed having problems and crisis, sitting back to back, empty space

Considering how much your thyroid gland affects how your body performs and behaves, it likely won't shock you to learn it has an effect on your sex drive as well. "With the exception of sexual issues related to menopause, I see [sexual issues related to hypothyroidism] more often than anything else in my female patients," nurse practitioner Lynn Moyer told WebMD.

Carpal tunnel

Black man holding his wrist in pain because of carpal tunnel syndrome

One of the more surprising signs of a potential thyroid problem may be carpal tunnel syndrome. In a 2019 article for the Mayo Clinic, internal medicine specialist Todd B. Nippoldt, MD, explains that this is because long-term hypothyroidism can damage the peripheral nerves, which help send information to and from the brain to the rest of the body.

Difficulty swallowing

older woman clutching throat, signs your cold is serious
Shutterstock/Aleksandra Suzi

In addition to hypothyroidism and hyperthyroidism, some patients also develop cancer of the thyroid, which is more common than you think. In fact, it's the most common form of cancer in women between the ages of 20 and 34, according to the American Society of Clinical Oncology (ASCO). The primary symptom? Difficulty swallowing.

Throat pain

Doctor Examining a Patient's Mouth Tongue Health

According to ASCO, another thyroid cancer symptom to watch out for is throat pain accompanied by a persistent cough. However, thyroid cancer often presents with no symptoms at all, so make sure you're seeing your doctor regularly regardless of whether or not you're experiencing anything out of the ordinary.

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