When you are hypothyroid, everything in your body slows down, including your reflexes, your ability to maintain your body temperature, and your ability to respond to your environment. This slowing down occurs from head to toe; these symptoms are discussed here in alphabetical order. These symptoms disappear once your thyroid hormone level is restored to normal.
Cardiovascular Changes
People with hypothyroidism often have an unusually slow pulse rate (between forty and seventy beats per minute) and blood pressure that may be too high. More severe or prolonged hypothyroidism can raise your cholesterol levels as well, and this can aggravate blockage of your coronary arteries. In severe hypothyroidism, the heart muscle fi bers may weaken, which can lead to heart failure. This scenario is rare, however, and you would have to suffer from severe and obvious hypothyroid symptoms for a long time before your heart would be at risk.
But even mild hypothyroidism may aggravate your risk for heart disease if you have other risk cofactors. For example, it’s not unusual if you are hypothyroid to notice chest pain (which may be confused with angina) or shortness of breath when you exert yourself. You may notice some calf pain, which is caused by hardening of the arteries and dysfunction of the muscles in the leg. Fluid may also collect, causing your legs and feet to swell.
Cold Intolerance
Because your entire metabolic rate has slowed down, you may not be able to fi nd a comfortable temperature. You may fi nd yourself wondering, “Why is it always freezing in here?” You will likely carry a sweater with you all the time to compensate for your continuous sensitivity to cold. You’ll feel much more comfortable in hot, muggy weather, and you may not even perspire in the heat.
Depression and Psychiatric Misdiagnosis
Hypothyroidism is linked to psychiatric depression more frequently than hyperthyroidism, but symptoms of depression may be masked or misdiagnosed in both cases, and thus can cause the psychiatric misdiagnosis. Psychiatrists even fi nd that hypothyroid patients sometimes exhibit certain behaviors linked to psychosis, such as paranoia or aural and visual hallucinations (hearing voices and seeing things that are not there). This used to be called “myxedema madness.” Interestingly, in some populations roughly 15 percent of patients suffering from depression are found to be hypothyroid.
Digestive Changes and Weight Gain
Because your system has slowed down, you may suffer from constipation, hardening of your stools, bloating (which may cause bad breath), poor appetite, and heartburn. Food will not move through your stomach as quickly, so you may experience acid refl ux (a condition in which semidigested food comes back up the esophagus). Because the lack of thyroid hormone slows down your metabolism, you might gain weight as well. But because your appetite may decrease radically, your weight could also stay the same.