Patients with hypothyroidism are diagnosed as having an underactive thyroid gland. What this means is their thyroid gland produces too little thyroid hormone. What exactly does this mean, and how does it affect you?

The thyroid gland is responsible for releasing thyroid hormone into the bloodstream to regulate functions in the body including our heart rate and breathing. Typically this includes the levels of T3 and T4 hormone in the body. These are the hormones that doctors usually measure to determine whether someone has hypothyroidism. Doctors also measure TSH (thyroid stimulating hormone). What does all of this mean? Let's find out.

T3, T4, and TSH Demystified

The thyroid gland produces thyroid hormones. The thyroid is affected by pituitary gland which rests up in the brain. The pituitary detects levels of thyroid hormones in the bloodstream, and if it detects that levels are deficient, it produces higher levels of a thyroid hormone, known as TSH, or thyroid stimulating hormone, that says, "Hey guys, we need more thyroid hormone."

This makes sense. That is why this hormone is called, "stimulating hormone" because it stimulates the body to produce more thyroid hormones.

The thyroid may not be producing enough hormones for many reasons. You may be injured or sick for example; you may have an autoimmune condition, so your body is not functioning properly because your immune system has mistaken the thyroid gland for a foreign invader. In cases like this, the body's immune system is actually attacking the thyroid gland, so it is not capable of producing enough thyroid hormone to begin with. The chemical messaging system is actually not working properly in this case, even though the TSH or stimulating hormone messenger may be saying, "Hey, we need more thyroid hormone here."

In cases like this, TSH may appear normal, but levels of T3 or T4 may be out of balance. If a doctor only measures TSH in a patient, they may not get an accurate picture of what is going on in the patient's body.

When TSH measures high, a doctor sees that the thyroid gland is not producing enough thyroid hormone, thus he or she can assume a person has hypothyroidism. So, higher TSH levels typically suggest hypothyroidism.

If the thyroid gland is producing too much thyroid hormone, the TSH levels may be much lower than normal, suggesting a patient has a condition known as hyperthyroidism, or high thyroid function.

Levels of circulating T4 and T3 can also be measured, which can help healthcare providers detect other thyroid problems. Free T4 and Free T3 as well as antibody tests can also provide doctors with more comprehensive information about a person's health condition.

The normal reference ranges for an individuals TSH level is usually between 0.4-3.0mlU/L, which is a fairly broad spectrum. Anything below 0.4 typically suggests someone may have hyperthyroidism, whereas anything over 3.0 may suggest hypothyroidism. Some specialists however, believe in borderline cases, and the acceptable for thyroid hormones can vary with different labs. However TSH between 1.3-1.8mlU/L would be considered optimal.

Because each person is unique and different, your doctor may have to rely on your individual health history and symptoms, and not just average reference ranges to determine what the right level of hormones are for you. A healthcare provider should assess levels of other thyroid hormones to see if they are out of range to determine whether supplementation or treatment is necessary.

Our bodies are complex and dynamic. Establishing reference ranges can be helpful, but they are not always useful, because everyone's metabolic system works in unique and different ways. What is important is to combine blood tests with your symptom picture and family history. This will provide your healthcare provider with the best method of diagnosing your condition and prescribing a plan of action.

If you are diagnosed with hypothyroidism, remember that this is very treatable. Your doctor may suggest pharmaceutical drugs to help control your condition, however you can also look at natural therapy options. There are many remedies available that will also be effective in balancing your thyroid hormones, but these do not cause the same side effects and will actually act to heal your thyroid gland at the same time, potentially avoiding a lifetime of pharmaceutical treatment.