No one likes feeling tired or confused about weight gain. Or constipated. Or cold. Or sad. 

Any of these experiences, it can be said, is a normal part of life. And we deal with them as they happen and move on. But if one or more of these persist, without much relief, then “You might have an underactive thyroid,” says Dr. Baker Machhadieh, an endocrinologist. 

An underactive thyroid, or hypothyroidism, can affect so much of a person’s comfort and health.

And it all revolves around an organ no larger than a golf ball. 

What makes it tricky?

Hypothyroidism affects roughly 8 to 10 million Americans, making it a fairly common diagnosis. In fact, the typical medicine used to treat it—levothyroxine—is one of the most prescribed in the world. 

Among those diagnosed, women are diagnosed twice as often as men. “That’s not only from women being more likely to see a doctor, which might be the case. But it is more common in women.” 

Thankfully, hypothyroidism isn’t hard to diagnose. That happens with a simple blood test. 

But among the millions diagnosed with hypothyroidism, Dr. Macchedieh says, “You can add more to that when we consider subclinical—before diagnosis—hypothyroidism.”

So why is it often still undiagnosed? Or why do people wait so long before seeing a doctor and getting a diagnosis? 

Hiding in everyday life

People often live with undiagnosed hypothyroidism because its symptoms are so general. When a symptom appears, on its own, it feels like there’s no cause for concern.

Early symptoms can include weight gain and fatigue. And who doesn’t deal with that?

Other common symptoms include

• Dry skin
• Dry, thinning hair 
• Depression 
• Difficulty remembering things 
• Feeling chilled or cold 
• Slowed heart rate 

“We tend to chalk these [symptoms] up to normal life,” Dr. Macchedieh says, “So it’s normally when someone has a constellation of symptoms that they see a doctor.”

While no one wants to see a doctor just because they’re tired or gained some weight, Dr. Macchedieh encourages people to schedule a visit if symptoms persist or disrupt daily life. If left untreated, hypothyroidism can lead to 

• A hoarse voice 
• Puffy, sensitive skin, especially the face
• Loss of hearing
• Lower heart rate 

In more severe cases, it can lead to a life-threatening condition called Myxedema, an aggressive swelling of skin, often in the face or lower legs.

#Hypothyroidism

As of late, though, hypothyroidism has become a talking point through one unlikely source: social media. Users post their experiences with symptoms—feeling fatigue, see sudden weight gain, etc.—and attribute it to hypothyroidism. Some share success stories that came from a supplement, diet, or lifestyle change—typically without doctor approval. 

This has led to viewers, especially teenagers, dangerously diagnosing themselves. A self-diagnosis can become a misdiagnosis, missing the true cause of someone’s symptoms. And that leads not only to an untreated cause but also to buying and using treatments that won’t help—or could hurt—symptoms. Popular self-diagnosis solutions for hypothyroidism are iodine or kelp supplements. While it’s true that a lack of iodine can lead to hypothyroidism, it’s not common issue for those living in the U.S. Iodine supplements should be avoided unless a doctor says otherwise.

“Social media is raising awareness of the disease, which is great,” Dr. Macchedieh says. “But the only way to diagnose hypothyroidism is with a blood test through your doctor.”

Doctors use blood tests to see how different hormone levels show the “delicate balance between your brain (pituitary gland) and your thyroid” 

Consider the thyroid

The thyroid—a butterfly-shaped organ just above the windpipe—helps regulate your body and its processes. It does this by creating two hormones the body uses—T4 and T3. 

“When you hear ‘thyroid hormone,’ we’re talking about T4 and T3,” Dr. Machhedieh says. “They’re technically separate, but we see them under the one umbrella of ‘thyroid hormone.’”

But of the two, “T3 is the active hormone.” So how does the body get more T3?

It actually converts (changes) T4 from the thyroid into T3. This conversion happens in organs throughout the body, after it has traveled through the bloodstream. 

Think of T3 as the “active ingredient” in your body’s many processes. It helps do a lot, including

• Metabolize food, turning nutrients into energy
• Regulate body temperature, keeping a stable internal temperature
• Develop the body, especially in children, growing the nervous system, bones, and tissues
• Maintain cardiovascular health, keeping proper functioning of the heart and blood vessels

An underactive thyroid, then, doesn’t produce enough T4 for the body to convert into T3 to use. And that can happen for a few reasons.

What causes hypothyroidism? 

A thyroid might become underactive after it’s damaged, including from radiation treatment or, sometimes, surgery. But its most common cause is an autoimmune disease called Hashimoto’s disease.

In people with Hashimoto’s, the immune system actually attacks the thyroid, “which causes the destruction of thyroid-hormone producing cells,” Dr. Macchedieh says. “And that leads to an underactive thyroid.”

Unfortunately, the cause of Hashimoto’s remains unknown. But an underactive thyroid, regardless of the cause, has become much easier to treat. 

Treating it typically involves replacing the missing thyroid hormone with levothyroxine, commonly called Synthroid. “Treatment becomes something of an art, though,” Dr. Machhedieh clarifies. “We measure the success of treatment based on two things: a patient’s lab results and their symptom response.”

“Be patient in the process,” he asks. “There’s no single dose that’s best for everyone.”

If other medicines are needed, your doctor will work with you to figure out what’s best.

Once the right dosage is found, patients tend to feel more energetic, happier, and more like themselves.

Testing negative > living with symptoms 

Hypothyroidism is a real disease. And it can affect your mental, emotional, and physical health.

Dr. Machhedieh knows it’s frustrating not to feel good. And especially when you don’t know what’s wrong. “I feel for the general public,” he says. “You might have a very mild disease for a long time before you seek help. But that’s why the medical community is available.” 

In his words: it’s better to go to the doctor and test negative for hypothyroidism than live life under the frustrating weight of its symptoms.