Normals of TestsTo help diagnose growth hormone GH deficiency or, less commonly, growth hormone excess; to evaluate pituitary hgh.lkm to monitor the effectiveness of treatment for excess production of GH. Usually several blood samples, drawn at timed intervals from veins in your arms; sometimes a single sample of blood, drawn following a fast and rest, after a period hgh.lkm strenuous exercise, or after ingesting a hgh.lkm sugar solution. You may be hgh.lkm to find your test results on your laboratory's website how does trenbolone e work hgh.lkm portal. However, you are currently at Lab Tests Online. You may have been directed here by your lab's website in order to provide you with background information about the test s you had performed. Lab Tests Online is an award-winning hgh.lkm education website offering information anova r example laboratory tests.
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To help diagnose growth hormone GH deficiency or, less commonly, growth hormone excess; to evaluate pituitary function; to monitor the effectiveness of treatment for excess production of GH. Usually several blood samples, drawn at timed intervals from veins in your arms; sometimes a single sample of blood, drawn following a fast and rest, after a period of strenuous exercise, or after ingesting a glucose sugar solution.
You may be able to find your test results on your laboratory's website or patient portal. However, you are currently at Lab Tests Online. You may have been directed here by your lab's website in order to provide you with background information about the test s you had performed. Lab Tests Online is an award-winning patient education website offering information on laboratory tests. The reference ranges for your tests can be found on your laboratory report.
They are typically found to the right of your results. If you do not have your lab report, consult your healthcare provider or the laboratory that performed the test s to obtain the reference range. Laboratory test results are not meaningful by themselves.
Their meaning comes from comparison to reference ranges. Reference ranges are the values expected for a healthy person. They are sometimes called "normal" values. By comparing your test results with reference values, you and your healthcare provider can see if any of your test results fall outside the range of expected values.
Values that are outside expected ranges can provide clues to help identify possible conditions or diseases. While accuracy of laboratory testing has significantly evolved over the past few decades, some lab-to-lab variability can occur due to differences in testing equipment, chemical reagents, and techniques.
This is a reason why so few reference ranges are provided on this site. It is important to know that you must use the range supplied by the laboratory that performed your test to evaluate whether your results are "within normal limits. Growth hormone GH is a hormone that is essential for normal growth and development in children. It promotes proper linear bone growth from birth through puberty. In both children and adults, growth hormone helps regulate the rate at which the body both produces energy from food metabolism and makes lipids, proteins, and glucose sugar.
It also helps regulate the production of red blood cells and muscle mass. Growth hormone is produced by the pituitary gland , a grape-sized gland located at the base of the brain behind the bridge of the nose.
It is normally released into the bloodstream in pulses throughout the day and night with peaks that occur mostly during the night. Because of this, a single measurement of the level of GH in blood is difficult to interpret and not usually clinically useful.
The value will be higher if the sample is taken during a pulse and lower if it is taken during a period between pulses. GH stimulation and suppression tests are therefore often used to diagnose GH abnormalities. See the "How is it used? Children with insufficient GH production grow more slowly and are smaller in size for their age.
Some children have GH deficiency at birth congenital , but some may develop a deficiency later due, for example, to a brain injury or tumor. These conditions can affect the pituitary gland, causing a decrease in pituitary function, resulting in a lowered production of pituitary hormones hypopituitarism. Sometimes, the cause of the deficiency is not known.
In adults, growth hormone plays a role in regulating bone density, muscle mass, and glucose and lipid metabolism. It can also affect heart and kidney function. Deficiencies may have begun in childhood or develop in adulthood.
A deficiency can develop, for example, because of damage to the pituitary gland caused by a head injury, brain tumor, or surgery or radiation treatment.
This can result in a decrease in pituitary hormones hypopituitarism. The deficiency in GH can lead to decreased bone density, less muscle mass, and altered lipid levels. GH deficiency is a very rare cause of these disorders.
Excess GH is most often due to a GH-secreting pituitary tumor usually benign. Too much GH in children can cause their long bones to continue to grow beyond puberty, resulting in the extremely rare condition, gigantism , with heights of 7 or more feet.
Those with excess GH may also have thickening of facial features, general weakness, delayed puberty, and headaches. Excess GH in adults can lead to the rare condition, acromegaly , marked not by bone lengthening but by bone thickening.
Although symptoms such as skin thickening, sweating, fatigue, headaches, and joint pain can be subtle at first, increased GH levels can lead to enlarged hands and feet, enlarged facial bones, carpal tunnel syndrome, and abnormally enlarged internal organs.
Excess GH can also cause skin tags and intestinal polyps. If left untreated, both acromegaly and gigantism can lead to complications such as type 2 diabetes , increased risk of cardiovascular disease , high blood pressure , arthritis , and in general, a decreased lifespan. Because growth hormone is released in pulses, a single measurement of the blood level is not normally clinically useful.
Therefore, testing for the suppression or stimulation of growth hormone release from the pituitary is usually done. After fasting for 10 to 12 hours, a blood sample is drawn from a vein in the arm. Then, under medical supervision, the suppression or stimulation procedure is performed.
This may involve the use of an intravenous IV infusion. Blood samples are then drawn from a vein or from the IV at timed intervals. Sometimes, a single sample of blood is drawn following a fast and rest or after a period of strenuous exercise. Follow any instructions you are given.
In most cases, a person should be fasting. Resting or strenuous exercise for a time period before collection may be required. Children and early adolescents who are being tested for GH deficiency should be prepared for treatment with sex steroids for a few days prior to testing. Such treatment reduces the number of falsely low GH responses to stimulation.
The health practitioner who is ordering the GH testing should provide the child's parents with a prescription for such medications. Some healthcare providers will also prescribe propranolol prior to testing to reduce the number of falsely low GH responses to stimulation.
Growth hormone GH testing is primarily used to identify growth hormone deficiency and to help evaluate pituitary gland function, usually as a follow-up to other abnormal pituitary hormone test results. GH testing is also used to detect excess GH and to help diagnose and monitor the treatment of acromegaly and gigantism.
Growth hormone is essential for normal growth and development in children and helps regulate metabolism in both children and adults. The pituitary gland produces and releases GH into the blood in pulses throughout the day. For more, see the "What is being tested? For example, hypothryoidism must be treated prior to testing for GH deficiency in children; otherwise, a falsely low GH result may be seen. Other hormone testing, such as thyroid testing , is typically done first to rule out other conditions that may cause similar symptoms.
GH deficiency is rare in children and adults. It is possible in adults if GH deficiency was diagnosed in childhood or there is a history of hypothalamic or pituitary disease. Suppression testing may be done when a pituitary tumor is suspected of causing excess GH and may sometimes be used along with IGF-1 levels and other hormone levels to monitor the effectiveness of treatment for these conditions.
If GH levels are not significantly stimulated during a GH stimulation test they stay lower than they should and the person has signs and symptoms of GHD and a low IGF-1 level , if it is measured , then it is likely that there is a GH deficiency that the health practitioner may treat. GH testing for GH deficiency should not be performed until a person's thyroid function has been evaluated. If hypothryoidism is present in a child, it should be treated and the child's growth rate evaluated before GH testing is considered.
If a person exercises vigorously and does not experience an increase in GH levels, then they may have a GH deficiency. This finding would need to be followed up with further testing.
GH suppression test If a person's GH levels are not significantly suppressed during a GH suppression test they stay higher than they should and the person has signs and symptoms of excess GH gigantism or acromegaly and a high IGF-1 level if measured , then it is likely that the person tested is producing too much GH. If someone is being monitored for a previous tumor, then increases in GH may indicate a recurrence.
Pituitary tumors are the most common cause of excess GH production, but they may also cause deficiencies.
The presence of a pituitary tumor can affect not only GH production but may also affect production of other pituitary hormones, such as ACTH Cushing syndrome or prolactin. If the tumor is relatively large, it may inhibit all pituitary hormone production and cause damage to the surrounding tissues.
Since GH is released by the pituitary in bursts, measuring GH levels in samples collected at random times is not very useful. There is too much overlap between abnormal results and normal daily variation. GH levels will usually be higher first thing in the morning and will increase with exercise and stress. Abnormal GH levels can usually be modified once the causes are identified. Synthetic GH is available to alleviate deficiencies in children treatment of adults with GHD is more controversial.
Combinations of surgery, medication, and radiation can be used to treat pituitary tumors that are causing excess GH production. The important thing is to identify GH abnormalities as soon as possible for good outcomes. If left untreated, a child with GH deficiency will continue to have a short stature compared to peers. Likewise, the bone growth changes associated with gigantism and acromegaly are permanent.
There can be long-term complications from GH abnormalities. Acromegaly, for instance, can cause colon polyps increasing a person's risk of developing colon cancer , diabetes , high blood pressure , and visual abnormalities. If a pituitary tumor permanently damages pituitary cells, then multiple hormone replacement may be necessary. Increased bone growth may also lead to trapped nerves carpal tunnel syndrome , arthritis , and weak bones. It should be noted that most cases of short stature are not due to GH deficiencies.
They can also be related to familial traits, a variety of diseases and conditions, and to other genetic disorders. Rarely, a person may have symptoms associated with GH deficiency but normal or elevated GH levels due to an inherited resistance to GH.
Besides growth hormone deficiency GHD , children may be treated with growth hormone replacement if they have:. This is also true of adults, whether or not they have documented GHD. The medicine has associated risks and side effects and is expensive.