TempoLife › Diagnosis code lookup › k21-9
K21.9 — Acid reflux (GERD) without inflammation
Stomach acid coming back up into the gullet, causing heartburn.
General information only — not a diagnosis or medical advice. Only a doctor can say what this code means for you. Seek medical help for anything urgent or worrying.
What it generally refers to
Gastro-oesophageal reflux disease means stomach contents rise into the oesophagus, typically felt as heartburn or a sour taste. This code is used when there is no visible inflammation of the gullet. It is often eased by meal timing, weight, avoiding trigger foods, and acid-reducing medicines.
Reading it in context
Codes like K21.9 are written for records and billing, so they are short by design. The same code can sit behind very different real situations, and the plan that matters — tests, treatment, follow-up — lives in the rest of your notes and in what your clinician tells you, not in the code alone.
Other common codes
J06.9 — Common cold / upper respiratory infection
A general code for an infection of the nose, throat or sinuses — usually a common cold.
I10 — High blood pressure (essential hypertension)
Raised blood pressure with no single underlying cause identified.
E11 — Type 2 diabetes
The common, adult-onset form of diabetes, where the body handles blood sugar poorly.
M54.5 — Low back pain
Pain in the lower back — one of the most common reasons people see a doctor.
F41.9 — Anxiety disorder (unspecified)
Ongoing anxiety that affects daily life, without a more specific label.
J45.9 — Asthma (unspecified)
A long-term airway condition causing wheeze, cough and breathlessness.
Source: WHO International Classification of Diseases, 10th revision (ICD-10). Description paraphrased into plain language. · checked 2026-09-04
Frequently asked questions
What does ICD-10 code K21.9 mean?
Gastro-oesophageal reflux disease means stomach contents rise into the oesophagus, typically felt as heartburn or a sour taste. This code is used when there is no visible inflammation of the gullet. It is often eased by meal timing, weight, avoiding trigger foods, and acid-reducing medicines.
Is K21.9 serious?
The code itself does not say. It names a category, not a severity. What it means for you depends on your own situation, which only your doctor can judge.
What should I do if I see this on my note?
Read it as a label, not the whole story, and ask the clinician who wrote it if anything is unclear. For symptoms that worry you, contact a doctor or pharmacist.
Bring the full picture to your doctor
TempoLife tracks your weight, sleep and activity over time, so you can share real data, not guesses.