Recognizing Symptoms of Hypothyroidism
Definition of Hypothyroidism
In medical terminology, the prefix "hypo-" indicates that something is too low or has too little activity compared to normal.
Hypothyroidism refers to a state where there is too low a level of the thyroid hormones functioning in the body. This is most commonly due to low activity of the thyroid gland, itself. Hypothyroidism can also be due to a malfunction of the other glands that control the thyroid glands activity. This is called secondary hypothyroidism. In secondary hypothyroidism, the thyroid gland, itself is healthy, but the pituitary gland or hormone production from the hypothalamus in the brain that send signals to the thyroid are abnormal.
What Does the Thyroid Gland Do?
The thyroid gland is actually responsible for, or involved with many of the body's vital functions. The systems that regulate or result in energy production and expediter, both at the cellular and whole-body level are dependent on thyroid hormone, at least in part, for regulation. Through either direct or indirect action, nearly every major organ system can be affected if the thyroid isn't functioning properly.
The thyroid gland secretes the hormones called T3 and T4. These are the "thyroid hormones". T3 is most active in the body. Production of these hormones by the thyroid gland is controlled by a "negative feedback loop". This means that when there is enough, or too much thyroid hormone in the bloodstream, a signal is sent to slow or stop production of more thyroid hormone.
Normal production of thyroid hormone is regulated by TSH- thyroid stimulating hormone- secreted by the pituitary gland in the brain. TSH production, in turn, is affected by TRH- thyroid releasing hormone- from the part of the brain called the hypothalamus. Various body signals and chemicals can signal the hypothalamus to increase or decrease production of TRH, which affects production of TSH, which controls how much thyroid hormones are made and released by the thyroid gland. Confused? Here's the simple version.
Imagine this as a loop- the body sends signals to the hypothalamus up high in the brain. The hypothalamus relays the message to the pituitary gland at the base of the brain. The pituitary sends out TSH (thyroid stimulating hormone) in higher amounts when more thyroid hormones are needed by the body. The body sends signals, and so on...
Symptoms of Hypothyroidism
Knowing that the thyroid gland makes hormones that are necessary for 'homeostasis' or maintenance of normal body functioning, makes it easier to understand why there are so many and so varied symptoms.
Symptoms of hypothyroidism can be quite non-specific, meaning they can be the same symptoms that show up in other conditions. So, no diagnosis can be made here for anyone without a complete history and work up by a doctor who sees you in person.
Overall, hypothyroidism causes slowing of metabolism and energy generation throughout the whole body. Some of the most common symptoms (things you notice) of hypothyroidism are:
- Cold intolerance
- Dry, itchy skin
- Swelling of the face or joints
- Changes in menstrual cycles in women
- Thinned hair
- Memory deficits
- Weight gain or difficulty losing weight
Other signs (things your doctor might notice) of hypothyroidism include:
- Slowed heart rate
- Other changes on an electrocardiogram (EKG or ECG)
- Low blood pressure
- Goiter- an enlarged thyroid gland
- Mental status changes or coma in severe, long-standing, but untreated disease.
Most of the time, hypothyroidism symptoms develop slowly over time. Often, they can be subtle and therefore go unrecognized. Because so many symptoms are non-specific and by themselves, not serious, they are often ignored or attributed to other causes.
Hypothyroidism is quite prevalent and may affect up to 5 percent of the American adult population. It is important to recognize and receive treatment for hypothyroidism since it can affect so many body systems and cause a decline in quality of life.
In its most severe form, extreme hypothyroidism leads to a condition called myxedema coma, which may lead to death if not prevented or quickly treated.
Diagnosis of Hypothyroidism
Because hypothyroidism can't be definitely diagnosed just based on symptoms, blood tests are done to confirm the diagnosis. The cause of the hypothyroidism can be sought once low thyroid function or hormone levels are confirmed. Further questioning and blood tests can help sort and seek possible causes and guide appropriate treatment.