my little over-achiever

[cellio]

At her checkup last week, Embla -- who's always been perfectly normal, medically speaking (I won't comment on personality) -- had lost weight and had an elevated heart rate. The vet who saw her did some routine blood tests, including the test for hyperthyroidism, which he suspected. (With hyperthyroidism, basically, the engine is constantly revving -- so appetite is normal but the cat loses weight, heart rate is high, and probably other stuff too.)

The relevant test here is something called T4. Normal is about 4 (I don't know 4 what). When Erik was diagnosed recently it was with a reading of 8.

Embla's was 70. My vet said she didn't know they went that high.

So, my instructions are to take the medicine we got for Erik (which is currently suspended for other reasons), and start giving it to Embla instead. She's only 11, so she's a good candidate for a permanent solution (radiation or surgery), but we have to do drugs first to make sure treatment doesn't cause other problems.

Edit: the test measures concentration of something (some enzyme, I think); the units are micrograms per deciliter. Not one I would have guessed. :-)

Comments

[baron-steffan.livejournal.com]

The relevant test here is something called T4. Normal is about 4 (I don't know 4 what)

Micrograms of levothyroxine per deciliter of serum. Human normal is 4.6 to 12.

Most lab tests are still expressed in milligrams (or fractions such as micrograms) per deciliter; it used to be called "milligrams percent". The modern way, according to Systeme Internationale metric standards, is in moles per liter, but I don't know that many institutions are actually using that.

[cellio]

Thanks for the information. I was at first struck by the idea that micrograms and decliters seem to be of wildly different magnitudes (like furlongs per fortnight), and that seems odd. But I suppose there's an argument for choosing units of measure that result in scores that aren't either too huge or too tiny; no one wants to read lab results of 0.00003 somethings, nor 30,000 (presumably, though WBC seems to run in the tens of thousands of whatever those units are).

[jerusha.livejournal.com]

A lot of medical/pharmaceutical measurements are in "*something*/dL", because that's *something* per 100 mL, which is the basis for percent by volume. (Properly, pharmaceutical percents come in four different flavors: %w/w, which is g per 100 g; %w/v, or g per 100 mL; %v/v, or mL per 100 mL, and (so rarely it's almost not worth mention) %v/w (mL per 100 g). The reason that g and mL are treated as similarly-sized units is due to the density of water (in SI 1 g/mL); the units for the percentage are specified because water's the only thing for which you can assume g and mL are interchangeable units.)

So if you give me g/100 mL, you're giving me percent. But if the number of grams is vanishingly small, you can switch to mg% (assumed to be w/v), or express the units more explicitly as mg/dL or mcg/dL (or μg/dL in older notation)