Thyroid Disorders: An Overview
When to suspect a thyroid disorder

Your thyroid gland performs an important function in your body: it directs every cell in your body to its proper function. Having too little hormone as a result of hypothyroidism puts you into a dragging slowdown. On the other hand, having too much hormone, called hyperthyroidism, races your engine, so you feel all revved up-as if you were burning out.
Feeling tired and chilly, having constipation or losing your hair are all signs that might indicate an overactive thyroid, but these symptoms could also come from overwork, or aging, or a dozen other causes. Feeling tense and overworked could mean stress, not thyroid problems. Consult your doctor for the proper blood tests to receive a diagnosis.
A sick thyroid that doesn’t produce enough hormone might lead to feeling tired and listless, feeling chilly, especially when other people are comfortable, dry skin, hair loss, constipation, brittle and slow-growing fingernails, leg cramps, sore muscles, depression, heavier periods for women, slower heart rate, erectile dysfunction in men, loss of interest in sex, weight gain due to fluid retention, and other symptoms.
An overactive thyroid, on the other hand, might lead to feeling too hot when others are comfortable, shakes and tremors of your hands, feeling nervous and irritable, sweating more than you used to, fingernails growing faster, muscle weakness, especially thighs and upper arms, faster heart rate, sometimes irregular rhythms and an erratic pulse, more frequent and looser bowel movements, for women, lighter periods, as well as difficulties in becoming pregnant or in carrying the child to term, for men, loss of interest in sex, erectile dysfunction, and eyes that appear larger than normal
Other thyroid problems show up when the thyroid gland is swollen or sore. 
Other red flags that might indicate thyroid diseases are an enlarging thyroid, called a goiter, is usually a sign that the gland is overworking but could be a failing thyroid trying to do better, lumps or nodules in the gland found by you or your doctor that may contain cancer or be overproducing thyroid hormone, thyroiditis, and soreness due to inflammation of all or part of the gland.
Your risks of getting diagnosed with a thyroid disorder may be increased if others in your family have thyroid or other immune-system problems.
The conclusion
Make an appointment to see your doctor who knows you and should be in the best position to decide if thyroid tests should be done if you think you have a thyroid problem. If your doctor won't order thyroid tests and you still think you have a problem, you can call the Thyroid Foundation of America for more information or a referral to a thyroid specialist in your area.