Frequent Symptoms
Most people with hyperthyroidism experience one or more of the following symptoms. While these symptoms typically come on gradually, they may begin abruptly, especially in young people. On the other hand, older people with hyperthyroidism tend to have fewer and less noticeable symptoms than younger people.
As you can see, hyperthyroidism can affect the entire body, top to bottom:
Temperature
Increased sweating, as the body produces more heat, is another common symptom of hyperthyroidism. This excess sweating is linked to heat intolerance, which means a person may have a hard time tolerating a warm environment or activities that further increase heat production, like exercise.
Skin/Hair/Nails
In addition to thinning hair and a softening of the nails, the skin of a person with hyperthyroidism is often unusually smooth and warm, due to a rise in blood flow.
Heart
Due to increased pumping of the heart, a person with hyperthyroidism will often notice their heart racing or pounding. Irregular heart rhythms (called arrhythmias) and high blood pressure may also occur with an overactive thyroid gland.
Lung
Shortness of breath, especially with exercise, is common in older people with hyperthyroidism. It occurs as a result of a weakness of their breathing muscles, as well as an increased demand for oxygen within the body.
Intestines
Digestive symptoms, like dyspepsia and frequent bowel movements/diarrhea, may occur in hyperthyroidism as a result of the increase in gut motility.
Weight loss, despite an increase in appetite, is due to both the increase in gut mobility (which leads to fat malabsorption) and metabolic rate (which means the body is burning through calories quicker than normal). While this increase in metabolism may initially energize people, eventually they become fatigued as the body tires out.
Neck
An enlargement of the thyroid gland (called a goiter) may occur in some people with hyperthyroidism, causing potential symptoms like a sore throat and/or neck discomfort. Neck swelling may become noticeable, especially when a person tries to put on a tie or scarf. A goiter may eventually cause problems swallowing or even breathing.
Urinary Tract
Urinating more often, during the daytime and nighttime, is common in people with hyperthyroidism.
Reproductive System
Due to an alteration of sex hormones in the body, women with hyperthyroidism may develop infrequent menstrual periods. With severe hyperthyroidism, a woman may stop menstruating (amenorrhea).
Since the excess thyroid hormone converts testosterone to estradiol (a type of estrogen), men may experience a decrease in their sex drive, erectile dysfunction, and swelling of their breast tissue (gynecomastia). In addition, sperm production is often reduced or abnormal.
Brain and Nerves
A tremor of the hands often occurs in hyperthyroidism, along with behavioral and personality changes, such as depression, anxiety, nervousness, and/or irritability. Insomnia, as well as difficulties with concentrating or remembering things, are also frequently reported in hyperthyroidism.
Complications
There are a few major complications that may result from having hyperthyroidism, especially if left untreated.
Eye
Some people develop eye issues (called Graves’ ophthalmopathy), which may cause gritty, red eyes or protrusion of the eyes due to swelling behind the eyeballs. In severe cases, double vision can develop.
Bone
Hyperthyroidism is linked to osteoporosis, which causes bone weakening, making a person more prone to breaking bones with even minor bumps or falls.
Heart
In hyperthyroidism, there is a high risk of developing atrial fibrillation, especially in older people. Atrial fibrillation is a common heart arrhythmia that can lead to serious problems like stroke or heart failure.
Thyroid Storm
Thyroid storm is a rare but very serious, potentially life-threatening condition that occurs in people with untreated hyperthyroidism. It may also be triggered by a stressful event like surgery, trauma, or infection.
Thyroid storm is characterized by exaggerated symptoms of hyperthyroidism, such as a very fast heart rate, high fever, diarrhea, agitation, delirium, and/or decreased consciousness.
Pregnancy
While mild hyperthyroidism in pregnancy does not usually cause problems for a mother and her baby, moderate-to-severe hyperthyroidism in a mother can lead to various complications.
For the baby, according to the American Thyroid Association, uncontrolled or untreated hyperthyroidism of the mother during pregnancy is associated with size that is small for gestational age, preterm birth, stillbirth, and possibly congenital malformations.
For the mother, potential complications of untreated hyperthyroidism include pre-eclampsia and, rarely, thyroid storm.
Fetal Neonatal Hyperthyroidism
For a pregnant woman with Graves’ disease (the most common cause of hyperthyroidism in pregnancy), there is a small risk that her baby will develop hyperthyroidism before birth (called fetal thyrotoxicosis) or be born with hyperthyroidism (called neonatal hyperthyroidism).
Some babies are born hyperthyroid while others take days or weeks (up to three) to develop hyperthyroidism. Neonatal Graves’ disease, the most common cause of hyperthyroidism in newborns, occurs when the mother passes the thyroid-stimulating antibodies to her child, causing the baby to have a temporary case of hyperthyroidism.
If your baby develops hyperthyroidism, some symptoms may include:
Low birth weightAn unusually small head circumference (microcephaly)Warm, moist skinIrritability and poor sleepFast heartbeatA dangerous accumulation of fluid, known as fetal hydrops (rare)
When to See a Healthcare Provider
If you are concerned you (or a loved one) is experiencing one or more symptoms of an overactive thyroid gland, be sure to see your healthcare provider for a proper evaluation. The good news is that your thyroid function can be easily checked with a simple blood test, called the thyroid-stimulating hormone (TSH) test.
Lastly, if you are taking antithyroid medications for hyperthyroidism and considering pregnancy, it’s important to seek guidance from your general practitioner and, perhaps, an endocrinologist. You want to be sure your thyroid function is well controlled prior to and during pregnancy.
FatigueMuscle weaknessNervousness or irritabilityInsomniaMood swingsHeat intoleranceTremorsDiarrhea or frequent loose stoolsWeight lossIrregular heartbeatIrregular periodsBrittle hairGoiter (an enlarged thyroid gland)
