Parathyroid conditions and calcium imbalance: Clinical

To be retired ⓘ

00:00 / 00:00



Parathyroid conditions and calcium imbalance: Clinical

USMLE® Step 2 questions

0 / 12 complete


USMLE® Step 2 style questions USMLE

of complete

A 55-year-old female presents to her family physician with pain in the fingers of her right hand. She is mildly confused and is unsure exactly how long she has had this pain. The patient's daughter, who accompanied her mother to the visit, says that the patient has complained about this pain for about a month and has been progressively more confused over the last week. She also says that her mother has been complaining of increased nausea for the last few months. An X-ray of the right hand shows thin bones with brown tumors. Based on the patient's history and symptoms, what is the most likely cause of her condition?


Content Reviewers

There are a number of ways you can measure calcium in the blood.

First, there’s total calcium levels and this is made up of three fractions.

About 40 percent of the calcium is bound to albumin and about 15 percent is bound to minerals and the remaining 45 percent freely circulates the body and it’s called ionized calcium.

Total calcium levels range between 8.5 to 10.5 milligrams per deciliter, while ionized calcium ranges between 4.8 and 5.7 milligrams per deciliter.

When total calcium levels fall below 8.5 milligrams per deciliter, it’s considered hypocalcemia and when total calcium levels rise above 10.5 milligrams per deciliter, it’s considered hypercalcemia.

Okay, let’s start with hypocalcemia.

Individuals with hypocalcemia can be asymptomatic or have symptoms like tetany - which are intermittent muscular spasms - and perioral tingling.

On clinical examination, there may be a positive Chvostek’s sign. That’s when the facial muscles contract in response to tapping the skin over the facial nerve, just 2 centimeters anterior to the ear.

Another sign is the Trousseau sign. That’s where a blood pressure cuff is placed over the individual’s arm and is inflated to a pressure above the systolic blood pressure and is held like that for 3 minutes.

A positive Trousseau sign is when there’s a muscle spasm in the arm and forearm.

Now, the first thing to do in hypocalcemia is redo the lab work to make sure that the reading is accurate.

If hypocalcemia is confirmed, then the next thing is to check albumin levels.

Since most of the total calcium is bound to albumin, any rise or fall in the albumin will affect total calcium levels, leading to pseudohypocalcemia.

Normal albumin levels are 4 milligrams per deciliter and normal total calcium levels are 10 milligrams per deciliter.

For every 1 milligram per deciliter drop in albumin, calcium levels lower by 0.8 milligrams per deciliter. So, based on this, the corrected calcium levels can be calculated.


The parathyroid glands are four small glands in the neck that produce parathyroid hormone (PTH), which plays a major role in regulating calcium in the body. High levels of PTH lead to hyperparathyroidism, whereas low levels can lead to hypoparathyroidism. Hyperparathyroidism leads to an increase in blood calcium levels, resulting in symptoms like fatigue, muscle weakness, bone pain, osteoporosis, and kidney stones.

Hypoparathyroidism leads to a decrease in blood calcium levels. This can cause symptoms like tingling in the fingers and toes, muscle cramps, and seizures. Hyperparathyroidism is treated by surgically removing the overactive parathyroid gland; whereas in hypoparathyroidism, calcium and vitamin D supplementation, and hormone replacement therapy can help manage the symptoms.


Copyright © 2023 Elsevier, its licensors, and contributors. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

Cookies are used by this site.

USMLE® is a joint program of the Federation of State Medical Boards (FSMB) and the National Board of Medical Examiners (NBME). COMLEX-USA® is a registered trademark of The National Board of Osteopathic Medical Examiners, Inc. NCLEX-RN® is a registered trademark of the National Council of State Boards of Nursing, Inc. Test names and other trademarks are the property of the respective trademark holders. None of the trademark holders are endorsed by nor affiliated with Osmosis or this website.