what is the luteinizing hormone test or the lh test?
Luteinizing hormone(LH) is a hormone secreted by the anterior pituitary gland. The pituitary gland is located at the base of the brain and is known as the “Master gland” of the body since it produces many hormones that travel through the body. The Luteinizing hormone regulates the production of oestrogen in women, and the production of testosterone in men and plays a large role in puberty, menstruation and fertility.
The LH blood test measures the amount of Luteinizing Hormone in your bloodstream. The amount of this hormone in women generally varies with age and may change throughout the menstrual cycle. It also changes with pregnancy. In men, Luteinizing hormone levels progressively increase with age and with the decline in testosterone levels. Luteinizing hormone levels can be measured by analysing blood samples or a urine sample.
why do i need this test?
There are multiple reasons a doctor may administer an LH blood test. Luteinizing hormone levels primarily relate to menstrual issues, fertility issues, and the onset of puberty.
A doctor may order this test when a child enters puberty too late or too early, a woman is having difficulty getting pregnant or has irregular menstrual periods, to check for onset of menopause, when men show signs of low testosterone levels, or when a pituitary disorder is suspected.
what other tests might i have along with this test?
In some cases, the doctor may prescribe an FSH (Follicle-stimulating hormone) Test. This hormone works along with the Luteinizing hormone. Follicle-stimulating hormone facilitates the production of estrogen and testosterone, while Luteinizing hormone regulates the production.
The FSH test measures the amount of Follicle-stimulating hormone found in your blood. This test is also a blood test.
what do my test results mean?
In women, high LH and FSH levels may indicate a problem with the ovaries. This is known as the primary ovarian failure. Low LH and FSH levels can indicate secondary ovarian failure. Secondary ovarian failure implies that another part of the body caused ovarian failure. This is often the result of problems with the areas of your brain that make hormones, such as the pituitary gland.
In men, high Luteinizing hormone levels can indicate primary testicular failure. Secondary testicular failure may be due to a brain-related cause. Low Luteinizing hormone levels may result in low testosterone levels which could lead to sexual dysfunction, lack of sexual interest or fatigue.
In children, high levels of Luteinizing hormone could cause early puberty. Normal or low Luteinizing hormone levels along with delayed puberty may be an indication of disorders such as ovarian or testicular failure or hormone deficiency.
how is this test done?
As with a regular blood test, a health professional will clean the surface of the skin with an antiseptic and will apply pressure to the upper arm which causes the veins to swell. A needle is then inserted into a vein and the blood is drawn and collected in a syringe.
Once the required amount of blood is collected, the needle is removed and the injected area is dressed to stop the bleeding. This procedure takes only a few minutes.
does this test pose any risk?
There are some risks associated with this test. Most of the risks are associated with the cleanliness and sterilization of the equipment. If not properly sterilized, infections may be acquired. Another risk may be fainting or feeling lightheaded due to the loss of blood.
In some cases, the blood may also accumulate under the skin and cause lumps or bruises.
what might affect my test results?
The variables that may affect your test results are your nutritional diet, lifestyle and any other existing medications you're currently on. You may need to stop taking birth control and other hormone pills for four weeks before the test as these may alter the hormone level.
Doctors should be informed if you're using any supplements or prescription medications before the test is administered.
The sample required for this test is a blood sample. This sample is collected from a vein, usually in the arm and is collected in a syringe or vial. This is referred to as venepuncture.
how do you understand this result?
In women, Luteinizing hormone levels vary based on age and throughout the menstrual cycle. Before menopause, the Luteinizing hormone level varies between 5 and 25 International units per litre and is even higher in the middle of the menstrual cycle.
After menopause, the Luteinizing hormone level varies between 14.2 and 52.3 International units per litre.
In men over the age of 18, Luteinizing hormone levels vary between 1.8 and 8.6 International units per litre.
Luteinizing hormone levels in children are normally very low.
how do i prepare for the test?
When it comes to blood tests, there aren’t many precautions you need to take. You may be asked to avoid eating or drinking for up to eight hours before the test is administered. Depending on what medications you take, your doctor will inform you whether or not you need to avoid them for some time before the test so that your results aren’t affected.
Woman should stop taking birth control or other hormone pills for up to four weeks before the test. Doctors should also be informed of other tests you’ve undergone in the recent past, as some substances- such as radioactive substances- may affect the results of the test.
Understanding results ofLuteinizing hormone (LH)
|1.2- 7.8 mIU/ml||MALE FEMALE|
|1.7-15.0 mIU/ml||Follicular phase|
|21.9- 56.6 mIU/ml||Mid cycle peak|
|0.6-16.3 mIU/ml||Luteal phase|
|14.2- 52.3 mIU/ml||II] Post menopausal|
*A Reference range is a set of values which helps the healthcare professional to interpret a medical test. It may vary with age, gender, and other factors. Reference ranges may also vary between labs, in value & units depending on instruments used and method of establishment of reference ranges.'
Testing of Luteinizing hormone levels helps to indicate a large variety of developmental, fertility-related abnormalities. This test provides ample information about disorders or conditions affecting ovaries, testicles or parts of the brain producing the Luteinizing hormone.