The thyroid gland is a butterfly-shaped gland located on the lower part of the neck in the front. Despite its small size, the thyroid has a massively important effect on almost every cell in the body.
Hypothyroidism is the most common thyroid disorder. The gland underperforms, and is not able to make appropriate levels of hormone. When the gland overproduces hormone, it is known as hyperthyroidism. While this is not common, it still has a big impact on someone’s health.
The autoimmune conditions related to the thyroid are known as Hashimoto’s disease, which is th most common condition, and Graves' disease.
According to the American Journal of Medicine, “Thyroid hormones modulate every component of the cardiovascular system necessary for normal cardiovascular development and function” (Grais and Sowers).
There are two main hormones produced by the thyroid — triiodothyronine (T3) and thyroxine (T4).
T3 specifically has the biggest effect on the heart. It affects both the contraction and relaxation speed when the heart pumps to push oxygenated blood through the body. It helps maintain vascular tone in the smooth muscles of the arteries, which affects blood pressure and how the blood actually gets from one area to another.
In those people with chronic hypothyroidism, their risk for atherosclerosis and high cholesterol greatly increases.
Proper amounts of thyroid hormone also affect the way that digestion works. This includes stomach emptying, absorption of nutrients, and motility.
Hypothyroid patients commonly report more constipation or going days between bowel movements, whereas hyperthyroid patients report more diarrhea or loose stools.
Hypothyroid patients also have slower gastric emptying from the stomach into the intestines, which can increase symptoms of bloating, belching and heartburn.
In addition to cardiovascular and digestive symptoms, those who suffer from thyroid disease often experience hair, skin and nail problems as well.
Hypothyroid patients are more prone to dry, rough or scaling skin, dry hair, hair loss, hair thinning, brittle nails or nails that break easilyd. They are likely to have water retention in the ankles, hands and under the eyes. Those who are hypothyroid are often cold due to a drop in body temperature from the loss of hormone.
Hyperthyroid patients might experience hair loss too, however their hair is often more likely to be greasy, as is the skin on their face. With too much thyroid hormone floating around, people feel warm or hot, and might sweat easily.
Both hypo and hyperthyroidism affect a woman’s cycle, and increase her risk for miscarriage or fetal death. Her cycle may become longer or irregular, and she may have heavier bleeding with clots.
As a result, she may also have a difficult time becoming pregnant. It is commonly recommended that women with menstrual irregularities, or who are looking to become pregnant, check their thyroid levels.
The most commonly tested hormone for the thyroid is the thyroid-stimulating hormone, or TSH. While this is important, it is essential to look at the big picture and evaluate the T3 and T4, as mentioned above with cardiovascular disease.
The autoimmune markers for Hashimoto’s are thyroglobulin antibody, or TgAb, and thyroid peroxidase antibody, although the TPO can be elevated with Graves' disease, along with thyroid-stimulating immunoglobulin, or TSI.
If you suspect that your thyroid may be less than optimal, consult with your health care provider about appropriate testing. Discuss any health concerns you are having, especially in relation to heart, digestive, hair/skin/nails and reproductive health.
1) Grais, I. and Sowers, J. (2014). Thyroid and the Heart.
2) Poppe, K, Velkeniers, B, and Glinoer, D. Thyroid disease and female reproduction.
3) Pustorino, S, Foti, M, Calipari, G, Pustorino, E, Ferraro, R, Guerrisi, O, and Germanotta, G. (2004). Thyroid-intestinal motility interactions summary.
4) Redmond, G. (2004). Thyroid dysfunction and women’s reproductive health.
5) Safer, J. (2011). Thyroid hormone action on skin.
6) Yayali, O, Kirac, S, Yilmaz, M, Akin, F, Dogangun, Y, Demirkan, N, Akdag, B. (2009).
Reviewed January 28, 2016
by Michele Blacksberg RN
Edited by Jody Smith