Albumin

Of all the proteins in your blood, albumin is the largest share, roughly sixty percent. Your liver makes well over ten grams of it every day, and it lasts a few weeks. It does two things. It keeps water in your blood vessels: without enough albumin fluid leaks into the tissues and you get swollen ankles or fluid in the abdomen. And it is the carrier of everything that does not dissolve in water by itself: calcium, zinc, fatty acids, bilirubin, thyroid and sex hormones and many medicines. That makes albumin a value about three things at once. About your liver, which makes it; about your diet, because without enough protein the liver cannot make it; and about inflammation, because with every inflammation the liver switches its production from albumin to inflammation proteins, and the value falls within days. That last one is in practice the most common reason for a low albumin, and the least alarming. Your report shows albumin in g/L. Normal is about 35 to 47 g/L for a man of 19 to 50 years and 35 to 45 g/L for a woman, and the band falls slowly with age. It is a concentration, so thickened blood gives a higher number, and standing upright lifts it a few percent compared with lying down.

Albumin is the protein value that shows whether your body is in build-up mode. Anyone who eats too little protein, on a strict diet, in a period of little appetite, getting older or eating plant-based without paying attention, sees albumin slowly fall, and an albumin at the low end goes together in older people with less muscle, slower recovery and more frailty. Enough protein at every meal, meat, fish, dairy, eggs or legumes, and strength training bring it back. For anyone who does sport or is recovering from surgery it is a measure of the reserve the body draws on. The second reason is that albumin makes other values readable. Well over forty percent of your calcium travels bound to albumin, so with a low albumin your calcium looks too low while the free calcium is fine; corrected calcium exists for that. Zinc travels on albumin too, and a low zinc with a low albumin says mainly something about the protein. And medicines that bind to albumin work more strongly when there is less albumin. The third reason is that a low albumin without inflammation and with enough protein points at a liver or kidneys. A liver making less through disease, or kidneys letting protein through into the urine, let albumin fall while CRP is normal. That is the combination you take seriously: low albumin, normal CRP, and then the liver values and the urine.

A low albumin means less production, more loss or dilution. The most common explanation first: an inflammation or infection, a liver condition, a kidney disease in which protein leaks into the urine, taking in too little protein, and rarely a gut disease in which protein is lost. Look first at CRP: if that is high, the low albumin is a consequence of it and recovers once the inflammation is over. If CRP is normal, ALT and bilirubin say whether it is the liver, protein in the urine whether it is the kidneys, and your eating pattern whether it is the diet. A high albumin is almost always blood thickened by drinking too little, or a tourniquet that sat for a long time. Drink normally and have blood drawn again. A genuinely too high production does not exist. Read albumin beside CRP, and beyond that beside ALT and bilirubin, creatinine and protein in the urine, and correct calcium for it. Have blood drawn normally hydrated, and compare over time in the same posture and at the same lab.