Abnormal thyroid levels are due to either the overproduction or underproduction of thyroid hormones, according to WebMD. Abnormal levels of thyroid hormones can cause discomfort, but in most cases, they can be well managed with proper medical attention .
The overproduction of thyroid hormones is known as hyperthyroidism, according to Mayo Clinic. Hyperthyroidism can speed up the body's metabolism and cause such symptoms as an irregular heartbeat, weight loss and nervousness.
The underproduction of thyroid hormones is known as hypothyroidism, reports Endocrineweb. Symptoms of hypothyroidism include fatigue, weight gain, hair loss, depression, muscle cramps, constipation, memory loss and increased sensitivity to the cold.
Medications, and in some cases, surgery, can be employed to manage thyroid abnormalities, says MedicineNet.