How It Feels
The blood sample is taken from a vein in
your arm. An elastic band is wrapped around your upper arm. It may feel tight.
You may feel nothing at all from the needle, or you may feel a quick sting or
There is very little chance of a problem from
having blood sample taken from a vein.
- You may get a small bruise at the site. You can
lower the chance of bruising by keeping pressure on the site for several
- In rare cases, the vein may become swollen after the blood
sample is taken. This problem is called phlebitis. A warm compress can be used
several times a day to treat this.
- Ongoing bleeding can be a
problem for people with bleeding disorders. Aspirin, warfarin (Coumadin), and
other blood-thinning medicines can make bleeding more likely. If you have
bleeding or clotting problems, or if you take blood-thinning medicine, tell
your doctor before your blood sample is taken.
A parathyroid hormone (PTH) blood test
measures the level of parathyroid
hormone in the blood. The test is used to help
hyperparathyroidism or to find the cause of abnormal
The normal values listed here-called a reference range-are just a guide. These ranges vary from lab to lab, and your lab may have a different range for what’s normal. Your lab report should contain the range your lab uses. Also, your doctor will evaluate your results based on your health and other factors. This means that a value that falls outside the normal values listed here may still be normal for you or your lab.
Results are usually available in 1 to 2 days.
pg/mL or 10-65
High PTH levels may be caused
- A parathyroid gland growth (hyperplasia) or a
- A low level of calcium in the blood. A low blood
calcium level can be caused by kidney disease, kidney failure, severe
vitamin D deficiency, or an inability of the
intestines to absorb calcium from food.
- Some types of cancer, such
as of the lung, kidney, pancreatic, or ovarian cancer.
Low PTH levels may be caused by:
What Affects the Test
Reasons you may not be able to
have the test or why the results may not be helpful include:
- Taking medicine that raises PTH levels. These
include lithium, furosemide, rifampin, anticonvulsants, thiazide
diuretics, and medicines that contain
- Taking medicine that lowers PTH levels. These include
cimetidine (Tagamet) and propranolol (Betachron ER, Inderal, Inderal
- Being pregnant or breast-feeding.
- Having high
cholesterol or triglyceride levels.
- Having a scan that uses a
radioactive tracer within 1 week of PTH
- Drinking milk or eating milk products right before the