The thyroid is a small gland at the base of the throat that makes hormones to regulate growth and metabolism. These hormones influence a variety of organs, so they can affect body temperature, weight, cardiovascular health, and fertility. Hypothyroidism occurs when the thyroid gland produces too little of these hormones.

If your thyroid hormone levels are too low, you may experience symptoms like fatigue, digestive problems, sensitivity to cold temperatures, and menstrual irregularities. Although there may be no cure for hypothyroidism, the condition can be managed with medication. If left untreated, hypothyroidism can lead to many complications, such as heart problems, nerve damage, and infertility.

Cardiovascular Problems

Your thyroid hormone level can significantly impact your cardiovascular health. Having a weak pulse is one specific symptom of hypothyroidism. Another symptom is an abnormal heart beat. A study published in the journal Circulation reported that hypothyroidism can decrease the volume of blood pumped out by the heart in each beat by 30 to 50 percent. Low levels of the triiodothyronine (T3) thyroid hormone are also associated with cardiac failure. Fortunately, most cardiac complications related to hypothyroidism can be treated with proper medication.  

Renal Complications

Hypothyroidism frequently lowers the kidney’s ability to excrete water. As a result, blood levels of sodium may be unusually low, or serum levels of creatinine may be unusually high. Replacing thyroid hormones can fix these complications. But if extremely low hormone levels persist, recovery from these renal disorders can take longer.

Nerve Damage

Hypothyroidism can cause symptoms such as muscle weakness or nerve damage Those with untreated hypothyroidism may also be more prone to carpal tunnel syndrome.


Hypothyroidism reduces fertility in both men and women. Thyroid hormones regulate the metabolism of sex hormones, which control the production of sperm and eggs. In men, low levels of thyroid hormones have been linked to erectile dysfunction, abnormal sperm morphology, decreased libido, and impotence. Men with primary hypothyroidism, caused by too little thyroid-stimulating hormone (TSH) from the pituitary gland, often also have low levels of testosterone.

Evidence from multiple studies suggests that menstrual disturbances are three times more frequent in women with hypothyroidism. Light or irregular menstruation is the most common symptom. Women with autoimmune thyroid disorder are also more likely to experience infertility.

Pregnancy Complications

Studies suggest that a deficiency of thyroid hormones during pregnancy may increase the risk of a miscarriage or other complications like preeclampsia or preterm birth. A recent comparison of hypothyroidism treatments during pregnancy suggests that some drugs can mitigate these effects. Tell your doctor if you’re pregnant or planning to become pregnant.

If you notice symptoms of hypothyroidism, talk to your doctor. Being proactive and treating hypothyroidism early can help avoid any major complications.