A before-and-after photo reveals a lump she never realized she had.

Add cold intolerance to the long list of health issues you can blame on the butterfly-shaped gland in your neck. "Always being cold is a telltale sign of hypothyroidism, which means your thyroid doesn't secrete enough thyroid hormone," says Dr. Phillips. Without the right level of this hormone, your metabolism slows, preventing your body's engine from producing adequate heat. Other signs of hypothyroidism are thinning hair, dry skin, and fatigue.Approximately 4.5% of Americans have this condition, and rates are higher in women who have recently been pregnant or are over age 60. If you suspect a thyroid problem, see your doctor, who can confirm the diagnosis with a blood test and get your thyroid out of the slow lane with prescription meds. Related: What Every Woman Should Know About Her Thyroid Gland
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The thyroid is a complex part of the body, so it's no wonder diagnosing thyroid-related diseases like Hashimoto's disease, Graves' disease, or thyroid cancer can be extremely difficult. Now, one woman is raising awareness of thyroid cancer symptoms on Twitter. Last Wednesday, Lorna Brown tweeted a photo of her neck before and after a thyroid operation.

In her post titled "Thyroid Cancer - What to Look for From Someone Who Knows," Brown explains the photo on the left was taken by her brother almost a year before her thyroid cancer diagnosis. "You can clearly see the lump on my neck, here in this picture. Yet we missed it at the time!" she writes. Brown goes on to explain that the lump on her neck is a telltale sign of thyroid cancer—something she never knew before her diagnosis. "Please check your neck, and look at others around you," she urges readers. "Most thryroid cysts are benign, but some aren't. Mine certainly wasn't."

Brown's suggestion is a smart one. More than 30 million Americans have a thyroid disorder and more than 60,000 Americans are affected by thyroid cancer annually. The most common symptom of thyroid cancer is a hard lump on the neck—but most patients experience no symptoms at all. Two in three cases of thyroid cancer occur in people under age 55, and 75% of thyroid cancer cases occur women.

Doctors aren't sure what causes thyroid cancer. For now, the best thing you can do to protect yourself is to read up on these thyroid cancer facts and keep an eye on your neck.