When Your Thyroid Goes Awry
Does fatigue drag you down day  after day? Do you have brain fog, weight gain, chills, or hair loss? Or  is the opposite true for you: Are you often revved up, sweaty, or  anxious? Your thyroid gland could be to blame. This great regulator of  body and mind sometimes goes haywire, particularly in women. Getting the  right treatment is critical to feel your best and avoid serious health  problems.
What Is the Thyroid Gland?
The thyroid is a butterfly-shaped  gland in the front of the neck. It produces hormones that control the  speed of your metabolism -- the system that helps the body use energy.  Thyroid disorders can slow down or rev up your metabolism by disrupting  the production of thyroid hormones. When hormone levels become too low  or too high, you may experience a wide range of symptoms.
Symptom: Weight Gain or Loss
An unexplained change in weight  is one of the most common signs of a thyroid disorder. Weight gain may  signal low levels of thyroid hormones, a condition called  hypothyroidism. In contrast, if the thyroid produces more hormones than  the body needs, you may lose weight unexpectedly. This is known as  hyperthyroidism. Hypothyroidism is far more common.
Symptom: Swelling in the Neck
A swelling or enlargement in  the neck is a visible clue that something may be wrong with the thyroid.  A goiter may occur with either hypothyroidism or hyperthyroidism.  Sometimes swelling in the neck can result from thyroid cancer or  nodules, lumps that grow inside the thyroid. It can also be due to a  cause unrelated to the thyroid.
Symptom: Changes in Heart Rate
Thyroid hormones affect nearly  every organ in the body and can influence how quickly the heart beats.  People with hypothyroidism may notice their heart rate is slower than  usual. Hyperthyroidism may cause the heart to speed up. It can also  trigger increased blood pressure and the sensation of a pounding heart,  known as heart palpitations.
Symptom: Changes in Energy or Mood
Thyroid disorders can have  a noticeable impact on your energy level and mood. Hypothyroidism tends  to make people feel tired, sluggish, and depressed. Hyperthyroidism can  cause anxiety, problems sleeping, restlessness, and irritability.
Symptom: Hair Loss
Hair loss is another sign that your  thyroid hormones may be out of balance. Both hypothyroidism and  hyperthyroidism can cause hair to fall out. In most cases, the hair will  grow back once the thyroid disorder is treated.
Symptom: Feeling Too Cold or Hot
Thyroid disorders can  disrupt the ability to regulate body temperature. People with  hypothyroidism may feel cold more often than usual. Hyperthyroidism  tends to have the opposite effect, causing excessive sweating and an  aversion to heat.
Other Symptoms of Hypothyroidism
Hypothyroidism can cause many other symptoms, including:
- Dry skin and brittle nails
- Numbness or tingling in the hands
- Constipation
- Heavy menstrual periods
Other Symptoms of Hyperthyroidism
Hyperthyroidism can also cause additional symptoms, such as:
- Muscle weakness or trembling hands
- Vision problems
- Diarrhea
- Irregular menstrual periods
Thyroid Disorder or Menopause?
Because thyroid disorders can  cause changes in your menstrual cycle and mood, the symptoms are  sometimes mistaken for menopause. If a thyroid problem is suspected, a  simple blood test can determine whether the true culprit is menopause or  a thyroid disorder – or a combination of the two.
Who Should Be Tested?
Everyone should be screened for thyroid  dysfunction every five years, beginning at age 35, according to the  American Thyroid Association. People with symptoms or risk factors may  need tests more often. Hypothyroidism more frequently affects women over  age 60. Hyperthyroidism is also more common in women and in people over  60. A family history raises your risk of either disorder.
Thyroid Neck Check
A careful look in the mirror may help you  spot an enlarged thyroid that needs a doctor's attention. Tip your head  back, take a drink of water, and as you swallow, examine your neck below  the Adam's apple and above the collarbone. Look for bulges or  protrusions, then repeat the process a few times. See a doctor promptly  if you see a bulge or lump.
Diagnosing Thyroid Disorders
If your doctor suspects a  thyroid disorder, a blood test can help provide an answer.  This test  measures the level of thyroid stimulating hormone (TSH), a kind of  master hormone that regulates the work of the thyroid gland. If TSH is  high, it typically means that your thyroid function is too low  (hypothyroid).  If TSH is low, then it generally means the thyroid is  overactive (hyperthyroid.) Your doctor may also check levels of other  thyroid hormones in your blood. In some cases, imaging studies are used  and biopsies are taken to evaluate a thyroid abnormality.
Hashimoto's Disease
The most common cause of hypothyroidism  is Hashimoto's disease. This is an autoimmune disorder in which the body  attacks the thyroid gland. The result is damage to the thyroid,  preventing it from producing enough hormones. Hashimoto's disease tends  to run in families.
Other Causes of Hypothyroidism
In some cases, hypothyroidism  results from a problem with the pituitary gland, which is at the base of  the brain. This gland produces thyroid-stimulating hormone (TSH), which  tells the thyroid to do its job. If your pituitary gland does not  produce enough TSH, your levels of thyroid hormones will fall. Other  causes of hypothyroidism include temporary inflammation of the thyroid  or medications that affect thyroid function.
Graves' Disease
The most common cause of hyperthyroidism is  Graves' disease. This is an autoimmune disorder that attacks the thyroid  gland and triggers the release of high levels of thyroid hormones. One  of the hallmarks of Graves' disease is a visible and uncomfortable  swelling behind the eyes.
Other Causes of Hyperthyroidism
Hyperthyroidism can also  result from thyroid nodules. These are lumps that develop inside the  thyroid and sometimes begin producing thyroid hormones. Large lumps may  create a noticeable goiter. Smaller lumps can be detected with  ultrasound.
Thyroid Disorder Complications
When left untreated,  hypothyroidism can raise your cholesterol levels and make you more  likely to have a stroke or heart attack. In severe cases, very low  levels of thyroid hormones can trigger a loss of consciousness and  life-threatening drop in body temperature. Untreated hyperthyroidism can  cause serious heart problems and brittle bones.
Treating Hypothyroidism
If you are diagnosed with  hypothyroidism, your doctor will most likely prescribe thyroid hormones  in the form of a pill. This usually leads to noticeable improvements  within a couple of weeks. Long-term treatment can result in more energy,  lower cholesterol levels, and gradual weight loss. Most people with  hypothyroidism will need to take thyroid hormones for the rest of their  lives.
Treating Hyperthyroidism
The most common treatment for  hyperthyroidism is antithyroid medication, which aims to lower the  amount of hormones produced by the thyroid. The condition may eventually  go away, but many people need to remain on medication for the long  term. Other drugs may be given to reduce symptoms such as rapid pulse  and tremors. Another option is radioactive iodine, which destroys the  thyroid gland over the course of 6 to 18 weeks. Once the gland is  destroyed, or removed by surgery, most patients must begin taking  thyroid hormones in pill form.
Surgery for Thyroid Disorders
Removing the thyroid gland can  cure hyperthyroidism, but the procedure is only recommended if  antithyroid drugs don't work, or if there is a large goiter. Surgery may  also be recommended for patients with thyroid nodules. Once the thyroid  is removed, most patients require daily supplements of thyroid hormones  to avoid developing hypothyroidism.
What About Thyroid Cancer?
Thyroid cancer is uncommon and is  among the least deadly. The main symptom is a lump or swelling in the  neck, but less than 10 percent of thyroid nodules turn out to be  cancerous. When thyroid cancer is diagnosed, it is most often treated  with surgery followed by radioactive iodine therapy or external  radiation therapy. 
Courtesy of: WEBMD