Underactive thyroid function (hypothyroidism) is a type of thyroid disorder in which production of thyroid hormone is far less than normal. The thyroid regulates the rate of energy production in the body's cells. Any problems to the thyroid may reduce the body's metabolism and make you feel sluggish.

Many factors can cause hypothyroidism. It can be inherited, or because of previous problems, such as nodules, goiter, thyroid cancer, previous thyroid surgery, treatment of hyperthyroidism, treatment for thyroid tumors, iodine deficiency, and other autoimmune diseases. Women in general have a higher risk to suffer this disorder. Also, if your body is highly acidic, your risk of thyroid disorder increases. Advancing age is another reason to be affected by this disorder.

In early stages of hypothyroidism, there are hardly any symptoms to detect it promptly. Common symptoms of underactive thyroid function in more advanced stages can include : fatigue, intolerance to cold, sluggishness, trouble getting up in the morning, depression, dry skin, dry hair, constipation, fluid retention, hair loss, cracked or chipping fingernails, low sex drive, weight gain, muscle aches, cramps. Some sufferers may also develop swollen thyroid gland. Low thyroid symptoms in women may include recurrent pregnancy loss, menstrual problems, PMS, and difficult menopause.

For serious underactive thyroid function caused by tissue destruction, external supplement of thyroid hormones is necessary to restore thyroid hormone levels. When the condition is caused by lack of iodine in the diet, dietary changes and iodine supplements will be part of the low thyroid treatment. Less serious, but painful hypothyroidism is sometimes also treated with hormone supplements. In these cases it is difficult to find the right dose, and treatment may result in hormone poisoning.

Most doctors prescribe Synthroid, Levoxyl or Levothyroxine for low thyroid treatment. You should work with your doctor to choose the right thyroid replacement for you. It should combine both the inactive and T4 hormone found in Synthroid and the active hormone T3, found in other medications.

Exercising regularly, following a proper low thyroid diet, taking necessary supplements that protect your thyroid (such as vitamins A and D, selenium, zinc and fish oil) and treating the root causes of your thyroid problems (like toxins or food allergies) all can help to normalize your thyroid function.

Finally, hypothyroidism increases your risk of degenerative diseases such as heart disease, cancer and arthritis and your risk of widespread infection. In severe cases, symptoms of underactive thyroid function may involve a massive decrease of the energy level in the body's cells that it cannot even sustain a basic level of metabolism, creating a life-threatening situation. Hence, if you suspect that you have this condition and you are not sure what to do, talk to your doctor for further advice and low thyroid treatment.