Blood pressure refers to the force that blood exerts on the walls of the arteries as it passes through them. Hypertension or high blood pressure occurs when there is an increase in this force. The Mayo Clinic says that hypertension is classified as primary and secondary hypertension. When there is no identifiable cause for hypertension, it is called primary hypertension. Secondary hypertension on the other hand has identifiable causes, such as certain medical conditions.
Pheochromocytoma
The National Institute of Child Health and Human Development reports that pheochromocytoma is a rare tumor that occurs in the adrenal glands. Though this tumor may or may not be cancerous, it is non-cancerous most of the time. The adrenal glands are located on top of the kidneys and secrete several hormones including epinephrine and norepinephrine. These two hormones help the body maintain blood pressure and cope with stressful conditions. In pheochromocytoma, there is excessive production of epinephrine and norepinephrine and this causes occasional or continuous high blood pressure.
Cushing's Syndrome
The adrenal glands also secrete a hormone called cortisol. It has several roles in the body such as regulating the immune system, breaking down lipids, glucose and protein. Cortisol also maintains blood pressure. Cushing's syndrome is a disease characterized by excessive secretion of cortisol.
In this condition, the body is exposed to high levels of cortisol for a long period of time. Signs of Cushing's syndrome include tiredness, weak muscles, high blood glucose, anxiety, increased thirst and urinating, a hump between the shoulders and high blood pressure or hypertension.
Hyperthyroidism
The thyroid gland is located in front of the neck and releases thyroid hormone. Hyperthyroidism is a disease that occurs when the thyroid gland secretes more thyroid hormone than the body needs. Hyperthyroidism can be caused by Graves' disease--an autoimmune disorder that attacks and destroys the thyroid gland, inflammation of the thyroid gland, too much synthetic thyroid hormone or by taking too much iodine.
Thyroid hormone regulates the metabolic rate of the body. It determines the way the body uses energy and when it is too much as is the case with hyperthyroidism, the rate at which the body functions increases. In hyperthyroidism, the heart beats faster, there is too much sweating, anxiety and increased blood pressure or hypertension. The increased heart rate and pumping action of the heart leads to hypertension in hyperthyroidism as stated by "100 questions and answers about hypertension" by William Muir Manger and Ray Wallace Gifford.
References
- Mayo Clinic:
- The National Institute of Child Health and Human Development: Pheochromocytoma
- National Institute of Diabetes and Digestive and Kidney Diseases: Cushing's Syndrome
- "100 questions and answers about hypertension"; William Muir Manger, Ray Wallace Gifford; 2000
- Merck manuals Online Medical Library: Hyperthyroidism
