Of the estimated 20 million Americans who experience the symptoms of a thyroid imbalance, more than half don’t know they have a medical condition.

But the majority of them have an under active thyroid gland, called hypothyroidism, the most common thyroid disorder. Hypothyroidism occurs most often in women over 50. Roughly 15 per- cent of women over the age of 70 have the condition. The problem also runs in families, but its effects are varied and widespread. The hormone imbalance can lead to weight gain, depression, loss of energy, menstrual problems, muscle aches and other debilitating symptoms.

In general, untreated hypothyroidism leads to a poor mental and physical performance, says the Hormone Health Network, an informational re- source and leading authority on diseases that target the endocrine system.

Knowing your family’s medical history and the range of hypothyroid symptoms can help determine if your family is at risk. For example, you’re more likely to have an under active thyroid if more than one blood relative has had thyroid issues. Other symptoms include dry skin, hair loss, fatigue and constipation. Research suggests that untreated hypothyroidism can double the risk of heart attacks in older women. A study published in the Annals of Internal Medicine found that women with low thyroid activity are 70 percent more likely to have blockages in the aorta—the body’s main artery.

To increase chances of being diagnosed with hypothyroidism early, adults over 50 should get screened every few years. If your family is predisposed to thyroid issues, you should be twice as diligent.

According to a hypothyroidism fact sheet available via download from the Hormone Health Network, the hormone therapy used to treat hypothyroidism can prevent related health problems and further complications. Although hypothyroidism is hard to diagnose, treatment is relatively simple.

A synthetic thyroid hormone taken daily in pill form replaces what the body lacks. Once an appropriate dosage is established, the treatment is both effective and manageable.