Symptoms of thyroid trouble vary based on whether the thyroid is making too little or too much thyroid hormone, with hyperthyroid symptoms including increased heart rate and hypothyroid symptoms including reduced heart rate, notes WebMD. Both hyperthyroidism and hypothyroidism can cause goiters to develop in the neck.
Some of the symptoms of hyperthyroidism include weight loss, even though appetite is increased. Heart palpitations, high blood pressure, excess sweating and nervousness are also common. Trembling hands, muscle weakness and shorter or lighter menstrual periods are also signs of an overactive thyroid, according to WebMD.
Hypothyroidism, or underactive thyroid, is characterized by increased sensitivity to cold, tingling or numbness in the hands, slow mental processes, lethargy, depression and constipation, reports WebMD. Heavy menstrual periods and dry hair or skin are also caused by hypothyroidism.
Subacute thyroiditis is another thyroid problem characterized by mild to severe pain located in the thyroid gland and discomfort or pain when turning the head or swallowing. Tenderness in the thyroid area is another indicator of subacute thyroiditis, notes WebMD. Its symptoms generally occur after the flu, measles, mumps or other viral infections.
Feelings of intense drowsiness, lethargy and cold can indicate a myxedema coma, which is a potentially fatal thyroid condition, warns WebMD. Thyrotoxic crisis, which is indicated by delirium, rapid pulse, fever and agitation, is another complication caused by hyperthyroidism. Either of these conditions is a true medical emergency requiring urgent care.