Medically Reviewed by Brunilda Nazario, MD on January 18, 2021

When Your Thyroid Acts Up


You may know the classic signs of trouble with your thyroid -- a butterfly-shaped gland on the front of your neck. An overactive thyroid (hyperthyroidism) makes you sweat more, feel hot, lose weight, or makes your heart beat faster. An underactive thyroid (hypothyroidism) does the opposite. You might feel cold, gain weight, and get a slower heartbeat. But there are other less obvious signs that you need to learn about.

Foggy Brain


Your thyroid gland sends certain hormones to your brain to help it do all its many jobs. When hypothyroidism slows down the stream of those hormones, one side effect is "brain fog." You may find it hard to focus, remember things, or think clearly.

Mood Changes


Are you feeling sad and uneasy? There could be lots of reasons for it, but thyroid trouble is on the list. Depression is often the first sign of a thyroid problem. Anxiety is also linked to it. It's more common to feel depressed when you have hypothyroidism. Anxiety is common with hyperthyroidism.

Pregnancy Problems


Studies show that if you have an untreated thyroid disorder, you're more likely to have complications when you're pregnant, such as a condition called preeclampsia. You also have greater chances of a miscarriage or stillbirth. You could give birth prematurely or have a low-birth-weight baby.

Period Problems


Menstruation trouble can be a sign of a thyroid condition. Periods that are very light, very heavy, or irregular can all be symptoms. If you have no period at all, that can also be a sign. Girls with thyroid disorders may get their first period very early or very late.

Puffy Face


Does your face look doughy or swollen? It could be extra fluid your body is hanging onto because your thyroid isn't working right. You'll usually notice it most in your eyelids, lips, and tongue.

Blurry Vision


Sometimes a thyroid condition causes extra fluid to build up in tissues around your eyes. When that happens, thyroid eye disease can make the muscles that control your eyes get bigger. You might find you have trouble focusing or your vision may be blurry. You could also have double vision.

Carpal Tunnel Syndrome


Extra fluid shows up in other places in your body, too. The nerves that go to your hands travel through a tunnel of soft tissue near your wrist. When that tissue swells from too much fluid, it can put pressure on the nerves there. The numbness, tingling, and weakness that you get in your fingers is called carpal tunnel syndrome. 

Your Food Tastes Different


You taste with both your mouth and your brain. When your thyroid isn't acting the way it should, it can mess with one or both of these parts of the taste process. That can make foods taste different to you.

Low Libido


When your thyroid slows down, so does your metabolism. Your metabolism controls organs in your body that put out sex hormones. When you're low on these hormones, your sex drive takes a hit.

Hair Loss


It's normal to lose some hair every day. But if you're starting to notice your scalp more or see changes in the overall thickness of your hair, your thyroid could be the reason. Usually this is a problem only for severe thyroid disorders that you've had for a long time.

High Blood Pressure


An underactive thyroid can cause your blood vessels to become less flexible, which makes it harder for your heart to move blood to all the parts of your body. An overactive thyroid can increase blood pressure and make your heart beat faster.

Bathroom Trouble


Constipation can be a sign of hypothyroidism. So can having a bowel movement frequently. If you have thyroid trouble, you might also have runny, loose stools.

Show Sources


1) Getty

2) Getty

3) Getty

4) Getty

5) Getty

6) Getty

7) Getty

8) Getty

9) Getty

10) WebMD

11) Getty

12) Getty

13) Getty



Mayo Clinic: "Hyperthyroidism," "Hypothyroidism," "Hypothyroidism: Can it cause peripheral neuropathy?" "Carpal Tunnel Syndrome."

National Academy of Hypothyroidism: "Clearing the Air About Thyroid-Related Brain Fog," "Can Hypothyroidism Cause Water Retention and Edema?" "Low Thyroid Equals Low Libido."

Harvard Medical School: "When Depression Starts in the Neck," "Thyroid hormone: How it affects your heart."

Thyroid Foundation of Canada: "Depression and Thyroid Illness."

British Thyroid Foundation: "Psychological Symptoms and Thyroid Disorders," "Hair Loss and Thyroid Disorders."

Indian Journal of Endocrinology and Metabolism: "Recurrent pregnancy loss in patients with thyroid dysfunction."

Office on Women's Health: "Thyroid Disease."

Johns Hopkins Medicine: "Thyroid Disorders in Women."

American Academy of Dermatology: "Thyroid Disease: A Checklist of Skin, Hair, and Nail Changes."

Cleveland Clinic: "Thyroid Eye Disease."

American Family Physician: "Smell and Taste Disorders: A Primary Care Approach."

Rush University Medical Center: "When to Get Your Thyroid Checked."