Because most people and their doctors do not connect these symptoms to thyroid  disease, many people with hypothyroidism don’t know they have it.  Researchers found that almost 10% of these people had undetected hypothyroidism.
Hypothyroidism occurs in approximately one in eight women ages 35 to 65. After age 65, the incidence increases to one in five. One study of women over 60 from several senior citizens’ centers and ambulatory clinics found that as many as 24% were hypothyroid. Yet the disease is probably recognized the least in older people, because the symptoms are far more elusive in this age group. People over 60 with thyroid disease are much less likely than younger people to experience classic multiple symptoms. They may have only one symptom. For instance, it is not unusual for an older person to experience only memory loss or only depression, either of which is easily attributed to normal aging or other problems. In older people who do experience the classic symptoms of weight gain and fatigue, these symptoms of hypothyroidism are sometimes mistaken as typical signs of aging.

Only blood tests can confirm whether you are hypothyroid, so it is important to be aware of the symptoms and ask your doctor for a thyroid evaluation if you are over 60, have symptoms, or have any risk factors. Thyroid tests are not done routinely unless your doctor believes you are at risk or have symptoms. If left untreated, over time, hypothyroidism can have serious consequences. It increases your risk for high cholesterol, high blood pressure, atherosclerosis, and heart attack. In addition, a form of severe hypothyroidism called myxedema can develop over time, when the body slows to the point that it starts to shut down and may enter a coma.