Medical Specialty >> Nephrology

Doctors Lounge - Nephrology Answers

Back to Nephrology Answers List

If you think you may have a medical emergency, call your doctor or 911 immediately. Doctors Lounge ( does not recommend or endorse any specific tests, physicians, products, procedures, opinions, or other information that may be mentioned on the Site.

DISCLAIMER: The information provided on is designed to support, not replace, the relationship that exists between a patient/site visitor and his/her physician. Please read our 'Terms and Conditions of Use' carefully before using this site.

Date of last update: 10/09/2017.

Forum Name: Miscellaneous Nephrology Topics

Question: is slightly raised phosphorus level significant?

 woctams - Tue Aug 03, 2010 10:48 am

I am 31 years old and have a rather inexplicable case of osteoporosis -- I do have bone pain with it, especially over the bumps on my upper back, and sometime my skull hurts. My bloodwork generally comes back normal (hence the inexplicability) but this last time I had a phosphorus level taken (which I don't recall having before) and it came back as elevated at 4.7 mg/dl -- which is really only slightly elevated. My dr. tells me this isn't even significant: but it's the only clue thus far to why my bones are deteroriating, so I would like a second opinion just to make sure: is such a slight elevation significant? I don't eat a diet all that high in phosphorus (no junk foods, very little pre-packaged) & everything else is perfectly normal: in fact, great: I have low cholesterol, low all the bad stuff, am mostly in the middle on all the good stuff, though I'm at the baseline on sodium in spite of eating an incredibly high amount of salt :-). I have 'half and half' nails, and I don't know if that has any relevance whatsoever -- a dr. remarked on it one time. Is this something I should try to follow up on, or simply let drop?
I did have white blood cells in my urine (but I pass mucous in my urine all the time, and often have lower back pain that is not bone pain but is more on my sides). I don't know if that's significant either.
Thanks so much.
 Dr.M.Aroon kamath - Wed Aug 11, 2010 8:15 am

User avatar Hi,
Reddish-brown distal nail bands with whitish, ground-glass appearance of the proximal parts is called as brown arcs or ‘half and half nails’. Half-and-half nails are characteristically seen in chronic renal failure.

It affects fingernails more often than toenails. No correlation exists between the severity of azotemia and the depth of the distal colour band. The band usually tends to remain unchanged even after dialysis but has been reported to disappear after successful renal transplantation. The pathogenesis of half-and-half nail is unclear. Estimates of prevalence among patients with chronic renal failure are reported as 15%-50%.
However, it must be noted that "idiopathic" half-and-half nails have also been reported in the literature.

You have not given much information on your "osteoporosis", the radiological findings, and serum calcium levels and other labs.Your serum phosphorus levels will be considered normal according to some laboratory reference ranges.But an isolated serum phosphorus level can not be used for diagnosis.

However, for the sake of discussion, i would like to mention a few possibilities for hyperphosphatemia.

Hypocalcemia and hyperphosphatemia with low/normal parathyroid hormone (PTH) levels can be observed in hypoparathyroidism (HP). This disorder may follow an autosomal dominant (AD) or autosomal recessive (AR) mode of inheritance. It can be idiopathic as well.

Similar biochemical changes may also be seen in pseudohypoparathyroidism (PHP) type Ia and Ib, but the affected individuals usually have elevated PTH levels indicative of PTH resistance. Features of Albright’s hereditary osteodystrophy (AHO) are typically not seen in patients affected by familial forms of PHP-Ib.

Hypomagnesemia also may be associated with hypocalcemia and may also cause hyperphosphatemia. Some examples are as follows.
- Late-onset glycogenosis type II with renal magnesium wasting, hypomagnesemic hypocalcemia, hypocalciuria and osteopenia.

- Gitelman syndrome (GS), also known as 'familial hypokalemia-hypomagnesemia', is an autosomal recessive salt-losing renal tubulopathy that manifestsis with hypomagnesemia, hypocalciuria and secondary aldosteronism, which is responsible for hypokalemia and metabolic alkalosis.
Prevalence of heterozygotes for this condition is approximately 1% in Caucasian populations.

Although it is not possible to offer any likely diagnoses based on the information given, i feel that you should have your serum magnesium levels checked.
Best wishes.

| Check a doctor's response to similar questions

Are you a Doctor, Pharmacist, PA or a Nurse?

Join the Doctors Lounge online medical community

  • Editorial activities: Publish, peer review, edit online articles.

  • Ask a Doctor Teams: Respond to patient questions and discuss challenging presentations with other members.

Doctors Lounge Membership Application

Tools & Services: Follow DoctorsLounge on Twitter Follow us on Twitter | RSS News | Newsletter | Contact us