The thyroid is a gland that sits on the front of your neck, just below your Adam’s apple. And while it’s only two inches long, it can control many of your body’s essential functions. Thyroid hormones are used throughout your body, affecting a wide range of activities, including metabolism, growth and development, and body-temperature management.
Depending on how much or how little hormone your thyroid makes, you may often feel restless or tired, or you may lose or gain weight. Women are more likely than men to have thyroid conditions, especially right after pregnancy and after menopause.
So, what body systems does the thyroid affect?
- Digestive Tract
- The rate at which you digest your food is affected by your thyroid. Thyroid dysfunction can cause it to either speed up or slow down—each having its own set of symptoms.
- Reproductive System
- Thyroid hormones are vital for the female reproductive system's function since they maintain the metabolism and development of ovarian, uterine, and placental tissues.
- Nervous System
- Thyroid function plays a crucial role in proper cognitive development and many other aspects of nervous system activity.
- Musculoskeletal System
- Thyroid hormones are known to play an important role in muscle development, regeneration, and function.
- Circulatory System
- Thyroid hormones affect your heart rate, blood vessel elasticity, and cholesterol levels.
Your thyroid and the hormones it produces have a significant impact on your overall health. Therefore, people with thyroid issues, such as hyperthyroidism or hypothyroidism, can experience a wide range of symptoms. Let’s take a closer look at how your thyroid affects each system and function and how each one could be impacted by thyroid dysfunction.
How does the thyroid affect your digestive tract?
The hormones your thyroid produces affect the rate at which you digest your food, which can be impacted by conditions such as hypothyroidism or hyperthyroidism. Many people with chronic gastrointestinal problems cannot find relief because they have an undiagnosed thyroid condition.
Hyperthyroidism, or the production of too much thyroid hormone in your system, causes bodily functions to speed up. Digestive symptoms of an overactive thyroid can include difficulty swallowing, vomiting, diarrhea, lactose intolerance, liver problems, H. pylori bacterial infection, and weight loss.
Hypothyroidism, or the production of too little thyroid hormone in your system, can cause the body’s processes to slow down. Digestive symptoms of an underactive thyroid can include dyspepsia (chest pain), low stomach acid, poor absorption, constipation, gallstones, anemia, and bacterial overgrowth in the small intestine.
How does the thyroid affect your reproductive system?
Women are more likely than men to have thyroid disease. In fact, 1 in 8 women will develop thyroid problems during her lifetime. In women, thyroid function affects the menstrual cycle, ovulation, and pregnancy.
Because your thyroid helps control your menstrual cycle, too much or too little thyroid hormone can make menstruation very light, heavy, or irregular. Thyroid disease also can cause menstruation to stop for several months or longer.
Both hyperthyroidism and hypothyroidism can make it harder to get pregnant. This is because thyroid dysfunction can disrupt the hormones that cause ovulation. Hypothyroidism can also cause your body to produce more prolactin, the hormone that tells your body to make breastmilk. Too much prolactin can prevent ovulation.
It can be harder to diagnose thyroid problems during pregnancy because of the change in hormone levels that normally happen during this time. Still, it is especially important to check for problems before getting pregnant and during pregnancy. Hyperthyroidism and hypothyroidism can cause problems for both mother and baby, such as low birth weight, preeclampsia, miscarriage, and premature birth.
How does the thyroid affect your nervous system?
Thyroid hormones influence the development and function of the peripheral and central nervous system. Hypothyroidism can change how the nerves send signals between your brain, spinal cord, and body. This can cause a condition called peripheral neuropathy. Its symptoms include numbness, tingling, pain, or burning in the affected parts of your body.
In the cases of both hyperthyroidism and hypothyroidism, one can experience psychiatric symptoms, such as depression, anxiety, memory loss, and, in some severe cases, psychosis.
How does the thyroid affect your musculoskeletal system?
Thyroid hormone signaling is required for skeletal muscle development, function, and regeneration. Because of this, thyroid dysfunction can lead to myopathy, or muscle weakness due to dysfunction of muscle fibers. Both hypothyroidism and hyperthyroidism can cause myopathy.
In the case of hypothyroidism, people may experience weakness and cramps in muscles that are closest to the center of the body, such as the thighs or shoulders. This can lead to problems climbing stairs or combing your hair. Joint pain and stiffness are common symptoms as well.
For people experiencing hyperthyroidism, muscle weakness is a common symptom. Cramping and aches may also occur, but they are not as common as they are with hypothyroidism.
How does the thyroid affect your circulatory system?
Thyroid hormones influence the force and speed of your heartbeat, your blood pressure, and your cholesterol levels. Because of this, thyroid dysfunction can cause problems that can worsen heart health.
Hypothyroidism can affect the heart and circulatory system in several ways. Lower production of thyroid hormone slows your heart rate. Hypothyroidism also makes the arteries less elastic, and blood pressure rises in order to circulate blood around the body. Elevated cholesterol levels, which contribute to narrowed, hardened arteries, are another possible consequence of low thyroid hormone levels.
Hyperthyroidism can cause the heart to beat harder and faster and may trigger abnormal heart rhythms. One is atrial fibrillation, a disorganized rhythm in the heart's upper chambers. A related symptom is palpitations, a sudden increase in your heartbeat. People with hyperthyroidism may also have high blood pressure. In a person with clogged, stiff arteries, the combination of a forceful heartbeat and elevated blood pressure may lead to chest pain or angina.
Your thyroid and the hormones it produces affect your entire body. Because of this, thyroid dysfunction can manifest in a wide range of symptoms. A great first step to improving your overall health in the new year is to start with your thyroid health.
Take notes of the duration and intensity of any symptoms you have. Then, make an appointment with your St. Joseph and Texas A&M Health Network primary care physician to discuss potential causes.
Healthline | The Effects of Hypothyroidism on the Body
WebMD | What Does Your Thyroid Do?
US News| Digestion vs. Metabolism
NCBI | Thyroid hormones and skeletal muscle — new insights and potential implications