pth

I have had hypothyroidism for 8 years now, and for the past 7 my thyroid level has been consistent.  I began to experience similar fatigue symptoms about 6 months ago.  My doctor and then endocrinologist ran every test they could think of as to what would cause my fatigue.  Everything, including my standard thyroid test came back within the healthy range.  Finally, as a last resort (because my Calcium and Phosphorous levels had originally tested normal) they checked my PTH level.  That test came back with the Parathyroid level significantly low.  My endocrinologist thought the test must have been incorrectly, so she sent me back for the PTH, calcium, and phosphorous levels.  Again it came back the same, Calcium and Phosphorous levels within the healthy range, not even on the low end, but a significantly low PTH level.  My endocrinologist has no ideas as to why this might be, except that the test must have been, again, done incorrectly and is sending me back for a third set of identical tests.  Is there any reason my PTH could be low, while my calcium and phosphorous levels are healthy; could this be the reason for my fatigue?

[J.M. Keyes, MD]

Hi there,
A low PTH itself should not cause fatigue- the symptoms related to hypoparathyroidism are a result of the calcium being too low, rather than a low PTH, and your calcium is fine.  Fatigue is generally a symptom of hyperparathyroidism.

I agree with your endocrinologist- it does not make sense that you have a low PTH and a normal calcium  and phosphorus levels.  In trying to find some possible explanation, I reviewed some of my medical books and literature and can't find any case in which this happens.  Hopefully this third set of tests will come back with a normal PTH level so that you no longer have to wonder what is going on with this.

Best of luck,

JMK MD