Lack of focus
There is some evidence that an underactive thyroid can take a substantial toll on mental health. Thyroid hormone deficiency slows the body’s functions, including neurological functions. As a result, some people may have trouble concentrating and even have short-term memory loss. Having difficulty making decisions may also indicate an underactive thyroid, though such problems in executive functioning are more often caused by other conditions.
High blood pressure
Hypertension is not usually associated with thyroid problems. However, both hypo- and hyperthyroidism may cause high blood pressure, known as secondary hypertension. Excess thyroid hormone causes the heart to beat faster and harder, resulting in a faster heart rate and an increase in blood pressure.
Constipation, which is usually defined as having fewer than three bowel movements a week, is a very common symptom of hypothyroidism. When the thyroid gland doesn’t make enough hormones, the body’s functions, including bowel movements, slow down. The opposite can also be a sign of a thyroid condition — overactive glands can cause diarrhea or more frequent bowel movements.
The hormonal changes caused by a thyroid disease may also affect the reproductive system. Menstrual abnormalities are common among women who have a thyroid condition. Depending on whether the thyroid is under- or overactive, a period may be longer, heavier or lighter, or very irregular. This is why symptoms of thyroid problems in older women are sometimes thought to be caused by menopause. Hypothyroidism may also lead to women having difficulties conceiving. When thyroid hormone levels are too low, a woman may not be ovulating regularly.
Hypothyroidism may often cause dry skin, but other skin changes, including itchiness with a rash and coarse skin, are also possible. Insufficient thyroid hormones slow down metabolism, which reduces sweating, resulting in dryness. Also, the skin’s natural ability to heal itself may be affected, causing itchy skin.