According to symptoms and test results patient could be euthyroid, transintly hyperthyroid, subclinical, moderate or severe hypothyroid. The extreme manifestation of hypothyroidism myxedema coma is a rare condition and occurs most often in elderly people.
TSH raises in proportion to degree of hypothyroidism. Increased TSH is earliest evidence of hypothyroidism and normally is sufficient to make the diagnosis. However, the measurement of free form of T4 and T3 thyroid hormones and thyroid antibodies are helpful to establish the cause of hypothyroidism.
In the beginning of Hashimoto’s disease some people experience symptoms of hyperthyroidism before they progress to the hypothyroidism. The antibodies cause inflammation and the thyroid gland slowly dies off leading to the release of excess thyroid hormone and hyperthyroid symptoms. This period of transient hyperthyroidism is called hashitoxicosis.
The person could show the following hyperthyroid symptoms: anxiety, insomnia, nervousness, trembling, heart palpitations, high blood pressure, increased sweating, heat intolerance and rapid temporary weight loss. Once the hyperthyroid phase is over thyroid gland is unable to produce adequate amount of thyroid hormones and hypothyroidism occurs.
Euthyroid means normal thyroid function. Most euthyroid individuals have TSH between 0.4 and 2.5 mIU/L, and T4 and T3 in a normal range.
Early or subclinical hypothyroidism
TSH can be elevated up to 3-5.5 mIU/L even if thyroxine (T4) levels are within the normal reference range, indicating subclinical hypothyroidism. At this stage, the TSH test is especially useful because it could be pointing to the underactive thyroid function before some patients develop clinical findings, goiter, or abnormalities noticeable in other thyroid tests.
The most common and early present symptoms of hypothyroidism, such as fatigue, constipation, dry skin, and weight gain, are nonspecific and could be attributed to many other disease and conditions. These symptoms can also be present in subclinical hypothyroidism when TSH is in the range between 0.3 and 10 mIU/L but T4 and T3 thyroid hormones are normal.
At this stage TSH is usually between 5.5 and 10 mlU/L and T4 is decreased. In 20 to 30% of hypothyroid patients T3 may be normal. The T3 levels may not fall until the disease has further advanced because increased TSH stimulates thyroid to release more T3. Classic findings of hypothyroidism appear when T3 falls below normal level.
Mild cases of an underactive thyroid caused by autoimmune thyroiditis can begin with the symptoms of fatigue, weight gain, fluid retention, dry skin, brittle hair and constipation. Weight gain due to hypothyroidism is usually no greater than 10% of the baseline euthyroid weight and is mostly attributable to fluid accumulation.
A person has moderate hypothyroidism when TSH is in a range of 10 to 20 mlU/L and low free T4 and T3. Women with mild or moderate hypothyroidism generally are able to achieve pregnancy. It is important to detect and correct the hypothyroidism as soon as possible because of the following reasons:
- Restoring thyroid function helps to manage hypothyroid symptoms that expecting mothers may have developed
- Hypothyroidism and/or thyroid autoimmunity can increase risk of miscarriage and fetal death
- Low levels of thyroid hormones affect cognitive development of the unborn child and cause damage to its central nervous system. Recent studies show that up to 70% of children with attention deficit and hyperactivity disorders have been observed among those born to mothers who had low free T4 during the first trimester of pregnancy.
When TSH is higher than 30 mlU/L and free T4 and T3 are low hypothyroidism is considered to be severe. Some common symptoms are fatigue, brain fog, feeling cold, hair and skin changes, puffiness of the face, muscle and joint aches and pains, low sex drive and depression.
Hypothyroidism affects ovarian function and women with severe hypothyroidism and/or thyroid autoimmunity often have difficulty to conceive. In women of reproductive age, thyroid hormone therapy can reverse hypothyroidism and improve fertility.
If untreated hypothyroidism may progress to myxedema coma that is a life threatening condition characterized by very low thyroid hormone levels. The body cannot cope with stressors such as infections, cold weather, trauma and minor surgery. Certain drugs and the lack of prescription thyroid medication can also contribute to myxedema coma in the hypothyroid person.
The patient is not able to function normally and experiences confusion, weakness, low body temperature, swelling and difficulty breathing. This condition requires emergency care and high doses of thyroid hormone administrated intravenously.
Many patients continue to have hypothyroid symptoms despite being treated for hypothyroidism with thyroid medication. The main reason for this is that thyroid medication just replaces the missing hormones, however it does not address the cause of hypothyroidism. Watch a FREE presentation on why conventional hypothyroidism treatments do not work and how holistic approach helps to recover from hypothyroidism permanently.
P.S. There is a lot more to discover about Hashimoto’s thyroiditis, so sign up for Outsmart Disease blog updates and get FREE e-mail course Nutritional guide for Hashimoto’s disease to learn more.
Thyroid gland development and function. Guy Van Vliet, Michel Polak, Karger Publishers, 2007, p. 62
The role of thyroid autoimmunity in fertility and pregnancy. Poppe K, Velkeniers B, Glinoer D; Nat Clin Pract Endocrinol Metab. 2008 Jul;4(7):394-405.
Myxedema coma: diagnosis and treatment. Wall CR. Am Fam Physician. 2000 Dec 1;62(11):2485-90.