Calcium metabolismCalcium metabolism is the movement and regulation of calcium ions (Ca2+) in (via the gut) and out (via the gut and kidneys) of the body, and between body compartments: the blood plasma, the extracellular and intracellular fluids, and bone. Bone acts as a calcium storage center for deposits and withdrawals as needed by the blood via continual bone remodeling. An important aspect of calcium metabolism is plasma calcium homeostasis, the regulation of calcium ions in the blood plasma within narrow limits.
HyperparathyroidismHyperparathyroidism is an increase in parathyroid hormone (PTH) levels in the blood. This occurs from a disorder either within the parathyroid glands (primary hyperparathyroidism) or as response to external stimuli (secondary hyperparathyroidism). Symptoms of hyperparathyroidism are caused by inappropriately normal or elevated blood calcium leaving the bones and flowing into the blood stream in response to increased production of parathyroid hormone. In healthy people, when blood calcium levels are high, parathyroid hormone levels should be low.
Parathyroid hormoneParathyroid hormone (PTH), also called parathormone or parathyrin, is a peptide hormone secreted by the parathyroid glands that regulates the serum calcium concentration through its effects on bone, kidney, and intestine. PTH influences bone remodeling, which is an ongoing process in which bone tissue is alternately resorbed and rebuilt over time. PTH is secreted in response to low blood serum calcium (Ca2+) levels. PTH indirectly stimulates osteoclast activity within the bone matrix (osteon), in an effort to release more ionic calcium (Ca2+) into the blood to elevate a low serum calcium level.
Calcium in biologyCalcium ions (Ca2+) contribute to the physiology and biochemistry of organisms' cells. They play an important role in signal transduction pathways, where they act as a second messenger, in neurotransmitter release from neurons, in contraction of all muscle cell types, and in fertilization. Many enzymes require calcium ions as a cofactor, including several of the coagulation factors. Extracellular calcium is also important for maintaining the potential difference across excitable cell membranes, as well as proper bone formation.
Reference rangeIn medicine and health-related fields, a reference range or reference interval is the range or the interval of values that is deemed normal for a physiological measurement in healthy persons (for example, the amount of creatinine in the blood, or the partial pressure of oxygen). It is a basis for comparison for a physician or other health professional to interpret a set of test results for a particular patient. Some important reference ranges in medicine are reference ranges for blood tests and reference ranges for urine tests.
CalcitoninCalcitonin is a 32 amino acid peptide hormone secreted by parafollicular cells (also known as C cells) of the thyroid (or endostyle) in humans and other chordates in the ultimopharyngeal body. It acts to reduce blood calcium (Ca2+), opposing the effects of parathyroid hormone (PTH). Its importance in humans has not been as well established as its importance in other animals, as its function is usually not significant in the regulation of normal calcium homeostasis. It belongs to the calcitonin-like protein family.
Parathyroid glandParathyroid glands are small endocrine glands in the neck of humans and other tetrapods. Humans usually have four parathyroid glands, located on the back of the thyroid gland in variable locations. The parathyroid gland produces and secretes parathyroid hormone in response to a low blood calcium, which plays a key role in regulating the amount of calcium in the blood and within the bones. Parathyroid glands share a similar blood supply, venous drainage, and lymphatic drainage to the thyroid glands.
Vitamin DVitamin D is a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, and many other biological effects. In humans, the most important compounds in this group are vitamin D3 (cholecalciferol) and vitamin D2 (ergocalciferol). The major natural source of the vitamin is synthesis of cholecalciferol in the lower layers of epidermis of the skin, through a photo-chemical reaction of UVB light, from the sun exposure (specifically UVB radiation) or UVB lamps.
CalcitriolCalcitriol is the active form of vitamin D, normally made in the kidney. It is also known as 1,25-dihydroxycholecalciferol. It is a hormone which binds to and activates the vitamin D receptor in the nucleus of the cell, which then increases the expression of many genes. Calcitriol increases blood calcium (Ca2+) mainly by increasing the uptake of calcium from the intestines.
CholecalciferolCholecalciferol, also known as vitamin D3 and colecalciferol, is a type of vitamin D that is made by the skin when exposed to sunlight; it is found in some foods and can be taken as a dietary supplement. Cholecalciferol is made in the skin following UVB light exposure. It is converted in the liver to calcifediol (25-hydroxyvitamin D) which is then converted in the kidney to calcitriol (1,25-dihydroxyvitamin D). One of its actions is to increase calcium uptake by the intestines.
SarcoidosisSarcoidosis (also known as Besnier–Boeck–Schaumann disease) is a disease involving abnormal collections of inflammatory cells that form lumps known as granulomata. The disease usually begins in the lungs, skin, or lymph nodes. Less commonly affected are the eyes, liver, heart, and brain, though any organ can be affected. The signs and symptoms depend on the organ involved. Often, no, or only mild, symptoms are seen. When it affects the lungs, wheezing, coughing, shortness of breath, or chest pain may occur.
ErgocalciferolErgocalciferol, also known as vitamin D2 and nonspecifically calciferol, is a type of vitamin D found in food and used as a dietary supplement. As a supplement it is used to prevent and treat vitamin D deficiency. This includes vitamin D deficiency due to poor absorption by the intestines or liver disease. It may also be used for low blood calcium due to hypoparathyroidism. It is used by mouth or injection into a muscle. Excessive doses can result in increased urine production, high blood pressure, kidney stones, kidney failure, weakness, and constipation.
DiureticA diuretic (ˌdaɪjʊˈrɛtɪk) is any substance that promotes diuresis, the increased production of urine. This includes forced diuresis. A diuretic tablet is sometimes colloquially called a water tablet. There are several categories of diuretics. All diuretics increase the excretion of water from the body, through the kidneys. There exist several classes of diuretic, and each works in a distinct way. Alternatively, an antidiuretic, such as vasopressin (antidiuretic hormone), is an agent or drug which reduces the excretion of water in urine.
UremiaUremia is the term for high levels of urea in the blood. Urea is one of the primary components of urine. It can be defined as an excess in the blood of amino acid and protein metabolism end products, such as urea and creatinine, which would be normally excreted in the urine. Uremic syndrome can be defined as the terminal clinical manifestation of kidney failure (also called renal failure). It is the signs, symptoms and results from laboratory tests which result from inadequate excretory, regulatory, and endocrine function of the kidneys.
PheochromocytomaPheochromocytoma is a rare tumor of the adrenal medulla composed of chromaffin cells, also known as pheochromocytes. When a tumor composed of the same cells as a pheochromocytoma develops outside the adrenal gland, it is referred to as a paraganglioma. These neuroendocrine tumors typically release massive amounts of catecholamines, metanephrines, or methoxytyramine, which result in the most common symptoms, including hypertension (high blood pressure), tachycardia (fast heart rate), and diaphoresis (sweating).
Kidney stone diseaseKidney stone disease, also known as nephrolithiasis or urolithiasis, is a crystallopathy where a solid piece of material (kidney stone) develops in the urinary tract. Kidney stones typically form in the kidney and leave the body in the urine stream. A small stone may pass without causing symptoms. If a stone grows to more than , it can cause blockage of the ureter, resulting in sharp and severe pain in the lower back or abdomen. A stone may also result in blood in the urine, vomiting, or painful urination.
Primary hyperparathyroidismPrimary hyperparathyroidism (or PHPT) is a medical condition where the parathyroid gland (or a benign tumor within it) produce excess amounts of parathyroid hormone (PTH). The symptoms of the condition relate to the resulting elevated serum calcium (hypercalcemia), which can cause digestive symptoms, kidney stones, psychiatric abnormalities, and bone disease. The diagnosis is initially made on blood tests; an elevated level of calcium together with a raised (or inappropriately high) level of parathyroid hormone are typically found.
PrednisonePrednisone is a glucocorticoid medication mostly used to suppress the immune system and decrease inflammation in conditions such as asthma, COPD, and rheumatologic diseases. It is also used to treat high blood calcium due to cancer and adrenal insufficiency along with other steroids. It is taken by mouth. Common side effects with long-term use include cataracts, bone loss, easy bruising, muscle weakness, and thrush. Other side effects include weight gain, swelling, high blood sugar, increased risk of infection, and psychosis.
DigoxinDigoxin (better known as Digitalis), sold under the brand name Lanoxin among others, is a medication used to treat various heart conditions. Most frequently it is used for atrial fibrillation, atrial flutter, and heart failure. Digoxin is one of the oldest medications used in the field of cardiology. It works by increasing myocardial contractility, increasing stroke volume and blood pressure, reducing heart rate, and somewhat extending the time frame of the contraction. Digoxin is taken by mouth or by injection into a vein.
Anorexia (symptom)Anorexia is a medical term for a loss of appetite. While the term outside of the scientific literature is often used interchangeably with anorexia nervosa, many possible causes exist for a loss of appetite, some of which may be harmless, while others indicate a serious clinical condition or pose a significant risk. Anorexia is a symptom, not a diagnosis. Anorexia is not to be confused with the mental health disorder anorexia nervosa.
