Low inside the front of your neck lies a gland that produces hormones to help regulate the energy use and cell function in every system and tissue of your body. When that gland underperforms, the effects can be widespread. But while the condition, called hypothyroidism, is easy to treat, it’s not always easy to diagnose.

Numerous studies suggest that up to 14 percent of older people have undiagnosed hypothyroidism, likely because people tend to display fewer symptoms after age 60—often just one. If cognitive dysfunction is the only symptom, for example, few physicians will think to test the thyroid.

A host of symptoms Further complicating diagnosis, many of the possible signs of hypothyroidism can be easily attributed to other causes. If you’re experiencing one or more of the following symptoms, talk to your doctor about having your thyroid tested.

Fatigue. People with an underactive thyroid may feel tired, listless, and lacking in energy to perform daily tasks.

Weight gain. A sudden unexplained weight gain is a good reason to check in with your doctor.

Constipation. As digestive processes slow, you may notice more gut discomfort and difficulty with bowel movements.

Dry skin. You may also have more brittle hair and nails.

Cold intolerance. People with a slowed metabolism may feel chilly all the time and find it difficult to get warm in cold conditions.

Mental fogginess. Some people with underactive thyroid feel more forgetful or have trouble concentrating.

Hair loss. Disruptions in thyroid hormones can affect hair follicles, leading to gradual or sudden hair loss.

Eyebrow thinning. A distinctive loss of hair on the outer third of your eyebrows can be a sign of an underactive thyroid.

An enlarged thyroid gland. Both underactive and overactive thyroids can enlarge, creating a visible lump on the neck called a goiter.

Rising cholesterol levels. Thyroid hormones help to clear low-density lipoprotein (LDL) cholesterol particles from your bloodstream. When too little is cleared, that so-called “bad cholesterol” rises, along with overall cholesterol levels, leaving you more vulnerable to a buildup of plaque in your arteries.

Elevated diastolic blood pressure. The lower number in a blood pressure measurement may rise in people with hypothyroidism.

Getting a diagnosis

If you suspect that your thyroid may be underperforming, make an appointment with your physician for a workup. He or she will assess your symptoms ask about your personal and family history, and run some blood tests. Those tests usually include one for thyroid-stimulating hormone (TSH) and one for a hormone called thyroxine (T4). TSH is a hormone produced by the pituitary gland that stimulates the thyroid to make T4 and, in lesser amounts, another hormone called triiodothyronine (T3).

An elevated TSH level is the clearest sign of an underactive thyroid: It suggests that your brain is detecting low thyroid hormone levels, so TSH is rising to correct the imbalance. When you have a clearly elevated TSH level combined with a clearly reduced level of T4, you meet the criteria to be diagnosed with hypothyroidism.

However, results aren’t always that clear. If your hormone levels are just slightly abnormal, your doctor might want to rerun the lab work because levels can shift, and you don’t want to treat a problem you don’t have. In other cases, TSH levels are clearly elevated but T4 levels appear normal. In that case, your doctor may diagnose you with subclinical hypothyroidism, or a mildly underactive thyroid.


If you have a clear case of hypothyroidism, your doctor will usually prescribe synthetic T4. If you are diagnosed with subclinical hypothyroidism, many doctors take a more individualized approach, considering the severity of your symptoms, your family history, and other factors to decide whether you are likely to benefit from treatment.

Older patients may need to start with a lower dose of medication and slowly work up to the full dose to avoid putting too much stress on the heart and central nervous system. If, after starting on the medication, you notice an increase in angina, shortness of breath, or confusion, or have a change in sleep habits, let your doctor know right away.

Your symptoms may not disappear overnight, but they typically improve gradually over several weeks to months. Your dose may need to be adjusted a few times to achieve target TSH and free T4 levels as well as improvement in symptoms.

One caveat: Because the symptoms associated with an underactive thyroid can have multiple alternate causes, you may find that some symptoms don’t disappear because they’re being caused by another underlying issue.

Dietary support

In addition to medication, you can support your thyroid by eating a healthy, well-balanced diet with a few tweaks. Several foods and medicines interfere with thyroid medication absorption, so take your medication with water only. Wait at least 30 to 60 minutes before drinking coffee, tea, or milk. Wait at least four hours to eat soy-containing foods (tofu, soy sauce, soy milk). If you have an iodine deficiency, limit your intake of Brussels sprouts, kale, cabbage, cauliflower, turnips, and bok choy to no more than 5 ounces per day. These cruciferous vegetables may block the thyroid’s ability to use iodine.

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