Your thyroid is a little gland with big effects

Despite its small size, the thyroid gland has a huge job: To produce hormones that regulate metabolism, or the rate at which cells convert food and other substances into energy. Thyroid hormones influence every cell, tissue and organ, so when the gland isn't working properly, your whole body feels it.

If the thyroid produces too much hormone, it speeds up body functions. This condition, called hyperthyroidism, may lead to increased heart rate, excessive sweating, sleep trouble and weight loss.

More common: Hypothyroidism, when too little hormone is produced. As body processes slow, you may feel colder and more tired and notice drier skin, forgetfulness and weight gain. Ask your doctor about being tested. Other considerations:

Mood can be affected.

Anxiousness, nervousness and irritability are signs of an overactive thyroid; an underactive gland could lead to symptoms of depression. The more severe your condition, the more dramatic the mood changes. But with the right treatment, you can improve the symptoms of thyroid disease.

Supplements may hurt.

Research from the Mayo Clinic suggests over-the-counter "thyroid support" pills (commonly used for weight loss and to fight fatigue) are mostly ineffective. The study analyzed 10 thyroid supplements and found all but one contained amounts of two thyroid hormones intended only for prescription drugs because they can cause increased heart rate, palpitations and diarrhea.

You can lose weight with a sluggish thyroid.

It's true that people with hypothyroidism put on 5 to 10 pounds, mostly because of an accumulation of salt and water. When the condition is treated, you can expect a small weight loss. The same is true for hyperthyroidism -- any pounds lost are likely regained with thyroid hormone treatment.

Most goiters are not cancer.

You see a bump on your neck and think the worst, but in most cases, an enlarged thyroid gland (or goiter) is benign.

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