"Jumpstart your thyroid!" 

"Is your thyroid out of whack?"

"Feeling sluggish? It could be your thyroid." 

We've all seen headlines like these online or on magazines at the grocery checkout counter. They're so common that many women have learned to blame their thyroid for everything. From trouble losing weight to depression, and from fatigue to brain fog, boosting and treating the thyroid seems to be a quick and effective solution. 

"It's just not accurate," says Mary Samuels, M.D., endocrinologist at OHSU. "In reality these kinds of symptoms have a wide variety of causes." 

Thyroid disease isn't rare, but it's nowhere near as common as popular magazines would make you think. About 5 percent of young women have thyroid disease, and its frequency increases as women age. In older women, up to 20 percent have at least mild thyroid disease. 

The truth about your thyroid 

What the thyroid does 
The thyroid gland produces thyroid hormone, which has effects on almost every organ in the body. It's a very ancient hormone—all mammals and even amphibians have it. 

• Brain—mood, attention and focus, memory, ability to do complex tasks 
• Heart—the speed and strength of heartbeats 
• Muscles—function and strength 
• Bones—storage of calcium 
• Liver—function and metabolism 
• Digestive system—absorption of nutrients 
• Metabolism—how fast your body burns calories 

Thyroid disease 
There are three types of thyroid disease that impact your body in very different ways. 

Hypothyroidism is when the thyroid doesn't produce enough hormone. This is the most common type of thyroid disease, and it causes body processes to slow down. Symptoms can be slow metabolism, weight gain, dry skin, feeling cold, depression, fatigue, brain fog, muscle weakness, slow heart rate, and constipation. 
Worldwide, hypothyroidism is often caused by iodine deficiency. But in the United States, where nearly everyone gets enough iodine in their diet, the most common cause is Hashimoto's disease, an auto-immune disease that decreases thyroid function. 

Hyperthyroidism is when the thyroid produces too much hormone. Symptoms can be fast metabolism, anxiety, irritability, feeling hot, weight loss, diarrhea, rapid pulse, shakiness and tremors, and trouble staying focused. 
The most common cause is Grave's disease, an auto-immune disease that overstimulates the thyroid gland. In older women, a goiter may cause the overproduction of thyroid hormone. Rarely, excess iodine, certain drugs, or pituitary disorders could be the cause. 

Thyroid lumps or nodules may also cause thyroid disease. Most women who have lumps don't have any symptoms and discover the lump accidentally. Small lumps are common, especially as women age, and 95 percent of them are benign and need no treatment. The remaining 5 percent are thyroid cancer, which is nearly always curable when caught early. 

Could it be my thyroid? 

These long lists of symptoms make it easy to see why so many women are worried about thyroid disease. After all, many women are bothered by some of these symptoms. But it's important to remember that all of them have a wide variety of causes.  

The good news is that there is an inexpensive and extremely accurate screening test to determine whether your thyroid is functioning properly. This simple test determines the level of thyroid stimulating hormone (TSH) in the blood. An abnormal level, either too low or too high, indicates thyroid disease. A normal level almost always means that your thyroid is working, and not the cause of any symptoms you may have. 

"There's so much misinformation out there that it's easy for women to think they have a thyroid problem, even if their TSH level is normal," says Dr. Samuels. "Women should know that treating a healthy thyroid can be dangerous, causing organ damage." 

It also won't help with symptoms. If your thyroid isn't causing your fatigue, depression, or weight gain, then treating it won't change anything. Worse, it will keep you from finding and treating the true cause of your symptoms. 

The bottom line 

If you're bothered by many of these symptoms or concerned about your thyroid, see your primary care provider and have your TSH level tested. Then trust the results! Your provider can help you find the cause and best treatment of your symptoms, thyroid-related or not. To learn more, visit the American Thyroid Association's patient portal.