The luteinizing hormone (LH) blood test measure the amount of LH in the bloodstream. LH is a hormone released by the pituitary gland, which is located at the base of the brain. It provides valuable information about how well the testicles are making testosterone.
Why it's done
In men, LH stimulates the production of testosterone. The test is used to help diagnose or evaluate:
- Male infertility
- Pituitary gland problems
There is little risk in getting a LH test. When the needle is inserted to draw blood, some people may feel some pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or a slight bruise.
How to prepare
For men, there is nothing that you need to do ahead of time. You do not need to be fasting when the labs are drawn.
Normal LH levels will differ, depending on a person's age and sex. Normal values for men are as follows:
- Between the ages of 20 and 70: 0.7 - 7.9 IU/L
- Men over 70: 3.1 - 34.0 IU/L