The thyroid, a butterfly-shaped gland in the neck, is a powerful organ. It’s part of the endocrine system, and it plays a huge role in keeping your body’s metabolic hormone levels in line. Simply put, these metabolic hormones are essential for helping cells and tissues throughout your body use energy, and continue running at the right speed.
Despite its role as a major player in cell metabolism, thyroid problems are pretty common. They’re more common in women then men—in fact, one in eight women will develop thyroid problems during her lifetime, according to U.S. Department of Health and Human Services. When the thyroid malfunctions, and starts releasing too few or too many hormones, it can seriously throw off your body’s basic functions, including sleep, reproduction, appetite, and digestion.
There are six main thyroid conditions that can occur:
- Hypothyroidism—underactive thyroid
- Hyperthyroidism—overactive thyroid
- Thyroiditis—inflammation of the thyroid, which can cause over- or underactivity and often presents postpartum
- Goiter—enlarged thyroid, which can cause overactive thyroid
- Thyroid nodules—lumps on the thyroid, which can also cause overactive thyroid
- Thyroid cancer—a rare cancer that may present without symptoms, except for a lump in the neck or soreness
What causes the thyroid to malfunction isn’t exactly known, but it is believed that autoimmune disorders may be to blame in many cases. There also seems to be a genetic link. Pregnancy, high stress levels, and iodine deficiency (which is not something you see in the U.S.) are all connected to thyroid problems as well.
Since the thyroid has far-reaching effects, there are lots of different symptoms that can signal your thyroid is out of whack. Here are the most common ones to look out for.
- You’re gaining weight and can’t seem to lose it no matter what you do.
Gaining weight is one of the biggest signs of hypothyroidism. That’s because when your body doesn’t have sufficient thyroid hormone, metabolism throughout all of your tissues and cells slows down. Slower metabolism means less energy is being burned.
- Or, you’re mysteriously losing weight.
On the other hand, losing weight without trying is a sign of hyperthyroidism, thanks to your body’s amped up metabolism. It basically becomes too efficient for its own good.
Thyroid-related weight gain or loss typically happens gradually, Jason C. Baker, M.D., endocrinologist at Weill Cornell Medicine and New York-Presbyterian, tells SELF, and may not be noticeable at first. If your thyroid problem develops suddenly, the change in your metabolism could be quicker, but usually thyroid conditions are slow-developing, and your weight fluctuations will follow suit.
- Your appetite has changed.
Having an underactive thyroid can also decrease your appetite, since your body is using less energy, and an overactive one may stimulate it. So you may notice you’re eating less but gaining more weight, or vice versa.
- Your period is irregular.
“If a woman’s menstrual cycle is normal and starts to get more frequent and lighter, it can be a sign of an overactive thyroid,” Baker says. “Less frequent and heavier can mean it’s underactive.” Any time regular ovulation is disrupted, it can potentially increase your risk of infertility.
- You’re seriously fatigued or way too wired.
Energy fluctuations, for no apparent reason, are one of the biggest red flags that something’s up with your thyroid. Fatigue, even after getting a good night’s sleep or taking naps, is a sign of hypothyroidism. With less thyroid hormone and a slower metabolism, your body feels sluggish. With hyperthyroidism, you may experience a racing heart and feel jittery, “kind of like you’re too caffeinated,” says Baker. That’s because your thyroid hormone is signaling your body to “go” more than it should.
- Your mood is all over the place.
Imbalances in thyroid hormones can cause your mood to change drastically. “With hypothyroidism, some people feel a little depressed,” Baker says. Research suggests it’s because changes in thyroid function impacts the feel-good chemical seratonin in the brain. Those with hyperthyroidism may experience anxiety, nervousness, or agitation.
- Your skin is dry and your hair is brittle.
When the thyroid is underactive, skin is known to become drier than normal. “We’re not sure why it happens,” Baker says, “but it has to do with overall heath of skin cells and sebaceous glands,” being compromised when the thyroid is underactive. The hair problems, which can also mean hair loss, can happen later after the thyroid has been malfunctioning for some time, so you might not notice the hair changes until later. If your thyroid is overactive, your skin might be noticeably oilier, but hair loss can be a symptom here, too.
- You’re constipated or have diarrhea.
“Sometimes people with underactive thyroid might feel a little constipated,” Baker says. That’s because too little thyroid hormone can slow down digestion. The opposite is true with an overactive thyroid—digestion is stimulated, and can cause more frequent bowel movements or diarrhea.
- You have the chills or are extra sweaty.
Feeling cold all the time can be a sign of hypothyroidism. What you’re experiencing is an effect of slowed metabolism. On the other hand, hyperthyroidism can make you feel hot or frequently sweaty, as your cells are working in overdrive.