reflux
Meaning of reflux: Backward flow where a one-way arrangement is supposed to hold, and a word used far beyond the stomach it usually brings to mind.
Definition of reflux
Reflux is the flow of a fluid backward through a passage that normally carries it in one direction only. In everyday use it means stomach contents rising into the gullet, but the same word describes urine travelling back up toward the kidney and blood escaping backward through a leaking heart valve. It is a description of movement rather than a diagnosis.
Where in the body does it happen?
| Type | What flows backward | Usual consequence |
|---|---|---|
| Gastroesophageal | Stomach contents into the gullet | Heartburn, cough, hoarseness |
| Vesicoureteral | Urine from bladder toward kidney | Repeated urine infections, kidney scarring |
| Venous | Blood back down the leg veins | Varicose veins, swelling, skin changes |
| Valvular | Blood back through a heart valve | Breathlessness, a murmur, an enlarging heart |
Each has the same underlying story. A structure meant to permit flow in one direction only has stopped doing so, whether because a ring of muscle has weakened, a valve leaflet no longer seals, or an angle that formed a working barrier has been lost.
Why does the digestive kind cause trouble?
The stomach lining is built to sit in acid. The lining of the esophagus is not, so material rising into it irritates a surface with no such protection, producing the burning behind the breastbone known as heartburn. Acid is not the only culprit, since digestive enzymes and bile carried up alongside it do their own damage, which is why suppressing acid completely still leaves some people with symptoms. A small amount of gastroesophageal reflux after meals is normal and goes unnoticed; it becomes a disorder when it causes symptoms or visible injury.
What happens if it continues for years?
Repeated injury and repair can change the lining itself. In some people the cells of the lower gullet are replaced by cells resembling those of the intestine, a change named Barrett esophagus, which resists acid better but carries a small ongoing risk of becoming cancerous. Scarring can narrow the tube until food sticks. Material reaching higher can inflame the throat and voice box or be drawn into the airway, so the complaints produced are not always recognizably digestive.
Also known as
Used in a sentence
Reflux of contrast into the ureter was demonstrated during the study.
Good to know
Reflux names a direction of flow rather than a disease, and it occurs in the urinary tract and at the heart valves as well as in the gullet, so the word carries meaning only alongside the site involved.
Word origin
Where “reflux” comes from
Reflux joins the Latin re-, meaning back, with fluxus, from fluere, to flow.