What are the symptoms of thyrotoxicosis?

Patients who develop thyrotoxicosis may report a range of different symptoms. Most of these symptoms are related to exposure to excess amounts of thyroid hormone. Increased stimulation of the cardiovascular system may speed up the heart rate while promoting forceful contraction of the heart muscle. Patients may notice sensations that feel like their hearts are beating rapidly or forcefully within their chests. This sensation is called a palpitation. Palpitations may last for a few seconds or may be sustained for several minutes, depending on the severity of the underlying thyrotoxicosis. Patients who develop thyrotoxicosis may also note that they perspire more than usual. Some patients may not be able to tolerate warmer temperatures that feel perfectly comfortable to others around them. This symptom is called heat intolerance. In some cases, heat intolerance may be confused with hot flashes that many women start to experience as they enter menopause. Patients who develop thyrotoxicosis may report a substantial amount of weight loss due to changes in rates of energy consumption and metabolism. Some patients may also notice an increase in appetite. This may lead to confusing situations in which patients begin to notice that they are losing weight even though they are eating much more than usual. Patients who develop thyrotoxicosis may feel nervous, irritable, and restless most of the time. Changes in behavior may be noted by friends, coworkers, or family members. Some patients may begin to experience insomnia characterized by difficulty falling asleep and staying asleep. This may lead to exhaustion and fatigue that may be heightened by weakness related to changes in muscle strength and stamina. Some patients may notice that their hands shake uncontrollably when they try to hold them steady. This shaking may become more pronounced when a patient tries to pick up or hold a heavy object. Women of childbearing age who develop thyrotoxicosis may notice that their menstrual periods start to become scant and irregular. In severe cases, a woman’s menstrual periods may stop altogether for several months at a time. Some patients who develop thyrotoxicosis may begin to have more frequent bowel movements with passage of loose stools.