Hyperthyroidism is a condition where the thyroid gland produces and releases excess thyroid hormones into circulation. On the other hand, hypothyroidism refers to a condition where the thyroid gland produces and releases inadequate amounts of thyroid hormones. Since thyroid hormones are important in the regulation of metabolism, too much hormone or too little thyroid hormones affects body tissues. The bodily functions affected by malfunction of thyroid gland are those that are regulated by thyroid hormones and they include body temperature, body fat metabolism, heart rate, oxygen use, and menstrual cycles among others (Rosenthal, 2000).
Since these two conditions are the opposite of each other, there are several differences in the clinical and diagnostic findings that are observed in people with these conditions. However, some similarities are also observed in these conditions. The clinical presentations of hyperthyroidism and hypothyroidism differ in several aspects and these are due to interference with the metabolic processes. To begin with, in hyperthyroidism the heartbeat rate is increased whereas in hypothyroidism it is slowed and this is to cater for body’s altered oxygen needs (Karla, 2006).
Another thing is that in hyperthyroidism the patients are intolerant to heat but in hypothyroidism the patients are intolerant to cold (Karla, 2006). Due to changes in fat metabolism, in hyperthyroidism there is weight loss due to increased fat metabolism while in hyperthyroidism there is weight gain due to reduced fat metabolism (Karla, 2006). Changes in the way the body uses food to produce energy leads to frequent bowel movements in hyperthyroidism but in hypothyroidism there is constipation (Karla, 2006).
Another difference is that in hyperthyroidism the skin is moist but in hypothyroidism the skin is dry. Finally, in women with hyperthyroidism, the menstrual periods are scanty while in those with hypothyroidism the menstrual periods are heavy (Poppe & Velkeniers, 2004). Similarities that are seen in both cases are enlargement of thyroid gland (though in hypothyroidism the size can also be normal or reduced) and hair loss (Rosenthal, 2000). Another similarity is infertility in both cases (Poppe & Velkeniers, 2004). The diagnostic findings of these two conditions are different.
When a doctor suspects thyroid malfunction, they do commonly recommend blood tests and these are done to assess the level of thyroid hormones in blood as well as assess the levels of thyroid stimulating hormone (TSH). In patients with Hyperthyroidism, the blood levels of TSH are very low and at times are undetectable (Dayan, 2001). On the other hand, in hypothyroidism the blood TSH levels are in excess. Another diagnostic finding is raised blood levels of the thyroid hormones known as T4 and T3 in hyperthyroidism while in hypothyroidism its blood level is low (Dayan, 2001).
Another diagnostic test that is done involves oral administration of radioactive iodine after which radioactivity in thyroid gland is measured. In hyperthyroidism the activity is high while in hypothyroidism the activity is lowered (Burger, 2004). Another test that accompanies radioactive uptake test is the thyroid scan and the findings in hyperthyroidism is increased concentration of the radioactive iodine in the thyroid gland while in hypothyroidism there is decreased concentration of the radioactive iodine (Burger, 2004).
Non specific diagnostic findings include increased blood glucose levels in hyperthyroidism which are reduced in hypothyroidism, and low blood cholesterol and triglyceride levels in hyperthyroidism which are raised in hypothyroidism (Rosenthal, 2000). It is clear that hypothyroidism and hyperthyroidism presents a lot of differences in terms of clinical presentations and diagnostic findings. Since the most obvious presentation of thyroid gland dysfunction is goiter which is enlargement of thyroid gland, further tests should be done to determine the exact cause of the problem.