Hypothyroidism and hyperthyroidism dysfunction
The thyroid gland is the gland that lies in the neck on both sides of the trachea (windpipe). It consists of two lobes that are normally not palpable or unable to be felt by an examiner. The thyroid gland produces hormones that control the metabolic rate of the rest of the body. The glands hormones are the chemical messengers that determine the speed of all of the bodily processes in the, whether they occur slow or fast. The thyroid gland is stimulated to produce its vital thyroid hormones by the higher brain centers which release thyroid stimulating hormone (TSH). Thyrotropin releasing hormone released by the brain hypothalamus goes to the pituitary and causes the release of TSH. This TSH then travels from the brain pituitary gland to the bloodstream which reaches the thyroid gland and tells the thyroid to produce its thyroid hormones. TSH stimulates the cells in the thyroid to produce and release the hormones thyroxine and triiodothyronine that then go to all the cells of the body controlling the rates or speed of their function. If the body produces less of the thyroid hormones, the body slows down and vice versa if the body produces too much of the thyroid hormones the body speeds up its cellular functions. (2)
The brain hypothalmus releases thyrotropin releasing hormone (TRH), which travels to the pituitary gland causing the release of thyroid stimulating hormone (TSH), which then travels via the blood stream to the thyroid gland where it stimulates the specialized cells of the thyroid to produce thyroxine (T4) and triiodothyronine (T3) the two hormones that regulate the speed of the all cellular function in the body. When too much or too little of these hormones T4 and T3 exist in the body, the cellular functions either go too fast or too slow.
Hypothyroidism is when too little T4 and T3 exist in the body and cellular functions slow down. Hyperthyroidism is manifest when too much T4 and T3 exist in the body. (2)
There are numerous causes of low and high levels of T4 and T3 in the body, most of which can be figured out with commonly ordered inexpensive blood tests.
Symptoms of hypothyroidism are weakness, fatigue, lethargy, cold intolerance, decreased memory and concentration, difficulty with hearing, constipation, muscular cramps, joint aches, tingling and numbness sensations in the skin, mild weight gain, less sweating, excessive menstrual blood loss, depression, hoarseness of the voice and carpal tunnel syndrome. Signs seen by doctors in these patients are dry and coarse skin, dull facial expression, husky voice, swelling around the eyes, hands and feet, slow heart rate, cold body temperatures, lower systolic blood pressure, increased diastolic blood pressure, less body and scalp hair, delayed relaxation of DTRs and a larger thicker tongue.(1)
Hyperthyroidism is a state where energy production exceeds the bodily needs. This causes too much heat and symptoms of sweating and fever. Patients feel fatigued, have weakness, increased hunger and experience weight loss. They are agitated, anxious, emotional, and can become psychotic or comatose. They experience difficulties with concentration and memory. The patients defecate more than usual. They experience menstrual periods with less flow of blood or have no periods at all. They experience rapid heartbeat and sometimes this can result in chest pain. Signs seen by doctors are warm moist skin, swelling in the tibial area of the lower leg bones, bulging eyeballs where the eyes stick out from the orbits. These patients appear sweaty, have sweaty palms and other body parts. Men develop man boobs, and have low sex drive. High heart rates, enlarged heart and abnormal heart rhythms can be seen. The bones can be brittle due to less density of the bone structure and mineral contents. Tremors may be noted, muscle weakness and anxiety are common. (1)
Treatment is made in either condition with medications that help to increase or decrease the levels of the hormones or surgery to remove the over productive hormone tissues. Simple inexpensive blood tests and other imaging tests can determine the causes of the problems and the needs and types of therapy to treat the conditions.
- The 5 minute clinical consult 2012
- Pathophysiology : the biologic basis for disease in adults and children