What does reabsorption mean?
Reabsorption is the renewed uptake of a substance, most commonly used for the process by which the kidneys return water, ions, and other useful dissolved materials to the blood after filtering the blood into urine. In medicine and biology, the word is particularly associated with renal tubular reabsorption, although it can also describe renewed uptake in other organs or systems. The prefix re- indicates that the substance is being taken up again, not simply absorbed for the first time. The distinction is important: absorption is initial uptake, while reabsorption follows a prior movement, filtration, or separation. The term is formal and technical, but it makes a useful scientific concept accessible. It also highlights the body's recycling of useful materials and the careful balance between recovery and waste elimination.
nounThe process of absorbing something again, especially the return of water and dissolved substances to the blood by the kidneys after they have been filtered into the urine.
- The process of taking up a substance again, especially the movement of water, ions, and other solutes from the kidney filtrate back into the blood.
- More generally, the renewed uptake or recycling of a substance after it has been released, filtered, or transferred elsewhere.
"The kidney's tubules are responsible for the reabsorption of water and useful solutes from the filtrate."
"The kidney's tubules are responsible for the reabsorption of water and useful solutes from the filtrate."
"Following secretion, the compound may undergo reabsorption into the bloodstream."
The regular plural is possible but uncommon, because reabsorption is usually treated as a process rather than as a countable event.
"Renal reabsorptions of sodium and water were measured under different conditions."
Your kidneys reabsorb valuable water and solutes from millions of filtrate tubules, quietly recycling what the body still needs.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does reabsorption come from?
Reabsorption is a modern English formation made by combining re- with absorption. Absorption itself comes through Latin from absorbere, formed from ab- and sorbere, meaning “to suck in” or “drink in.” The related English words absorb, absorbent, and absorptive developed from the same Latin root, while reabsorption adds the explicit sense of taking something up again.
Related word forms
How reabsorption is actually used
Formal and chiefly technical, especially in biology, physiology, medicine, and pharmacology. It is more common in these fields than in everyday speech.
Easily confused with reabsorption
Absorption is the initial uptake of a substance, whereas reabsorption is a second or renewed uptake after the substance has been filtered, secreted, or otherwise moved away from its original destination.
Resorption can be synonymous with reabsorption in physiological contexts, but in bone and dental terminology it more often denotes the breakdown and removal of tissue.