Sometimes it can be hard to diagnose these problems because the symptoms are easily mistaken for other conditions. When the thyroid is overactive, the condition is called hyperthyroidism. Symptoms of this include weight loss, heart palpitations, weakness, heat intolerance and nervousness. When the thyroid is underactive, it's called hypothyroidism. Symptoms include weight gain, exhaustion, hair loss and depression.
Hypothyroidism is more common than an overactive thyroid, and it becomes more common with age.
Both overactive and underactive thyroid conditions can lead to serious conditions, like heart problems, if left untreated. A blood test can easily diagnose either condition, but because the symptoms can be subtle or just seem like ordinary consequences of growing older, doctors may not suspect thyroid problems. Hyperthyroidism can be treated with medicine or treatment to suppress the production of hormones. Hypothyroidism also can be treated with medication. Doctors at UT Southwestern Medical Center say if you recognize the symptoms of either thyroid condition, it doesn't hurt to ask your doctor if your thyroid could be the cause.