Mnemonic Monday: Too Many Monkeys*…Hypercalcemia!

By Molly Lewis

While nutritionists may tout the benefits of “three servings a day of milk, cheese, and yogurt,” having too much calcium in your blood does not end well! Excess dietary calcium is almost never the cause of hypercalcemia, though, so what does cause a patient’s calcium to rise above 10.2 mg/dL (2.8 mmol/L)?

 “Two CHIMPANZEES!!!!”

• Thyroid: hyper or hypo
• Calcium excess (eating too much, taking pills, IV administration)
• Hyperparathyroidism (for example: parathyroid gland adenoma)
• Immobility
• Idiopathic familial (Familial hypocalciuric hypercalcemia (FHH): a mutation in calcium-sensing receptor. Even though patient may have a calcium of 12mg/dL, no treatment is needed!)
• Medications (a patient taking thiazides or lithium, for example)
• MEN I or MEN IIa syndromes (for example: parathyroid hyperplasia)
• Milk-alkali syndrome (taking antacids containing calcium)
• Metastasis / Malignancy
• Paget’s disease
• Paraneoplastic syndrome (tumor producing PTHrP (PTH related peptide))
• Paraproteinemia (ex: myeloma)
• Pheochromocytoma
• Addison’s disease (Adrenal insufficiency) (acidosis? ? Ca2+ bound to albumin ? ? free/ionized calcium)
• Acromegaly
• Neoplasms- especially solid tumors
• Zollinger-Ellison Syndrome (due to association with MEN Type I)
• Excess vitamin D 
• Excess vitamin A
• Sarcoidosis / other granulomatous diseases (macrophages making vitamin D)

(Sorry, but I don’t have space to explain why all the conditions listed above cause hypercalcemia, but you can look them up for yourself if you want to know the full pathophysiology!).

(If you want, try to remember “Two CHIIMMMMPPPPAANZEES” to include all of the causes I listed).

For a simplified version, try this…

CHIMPANZEES
C = Calcium supplementation
H = Hyperparathyroidism
I = Iatrogentic (Drugs, such as Thiazides or lithium, or immobility after surgery)
M = Milk Alkali syndrome
P = Paget disease of the bone
A = Addison’s Disease
N = Neoplasia (common cause)
Z = Zolinger-Ellison Syndrome (MEN Type I)
E = Excess Vitamin D
E = Excess Vitamin A
S = Sarcoidosis

Stay tuned for a future hypercalcemia mnemonic about how to remember symptoms!

Bibliography:

mnemonic from Step-Up to USMLE Step 2 by Jonathan P. Van Kleunen MD – 2nd Edition- with quite a few additions by me that I have learned bit by bit over the last 2 ½ years!

*(Yes, I realize that a monkey is not the same as a chimpanzee…the alliteration of the M’s just sounded good!)

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