The DM2 medical abbreviation most often means diabetes mellitus type 2, the common form of diabetes in which the body does not use insulin well and blood sugar runs high. You will see it on problem lists, in medical history sections and on referral forms.
The same letters can also mean myotonic dystrophy type 2, an inherited muscle disease, in neurology and genetics clinics. In a primary care note that lists metformin and an A1c, the diabetes meaning is nearly certain. This guide covers the written variations, how to read DM2 in a real chart, and which clues point to each one.
At a glance
The DM2 medical abbreviation, word by word
DM is short for diabetes mellitus, and the 2 names the type. The word diabetes traces back to Greek for a siphon, a nod to the heavy urination that high sugar causes, and mellitus is Latin for sweetened with honey. Put together, DM2 tells the reader that the patient has the type of diabetes driven mainly by insulin resistance, where the body makes insulin but the cells respond poorly, and the insulin supply often dwindles as years pass.
The general term DM without a number leaves the type open, which is why many clinicians and coders prefer the more specific DM2 or T2DM.
Many ways to write the same diagnosis
Different hospitals and clinicians favor different versions, so a single patient's records may show several of them.
| Form | Where it tends to appear |
|---|---|
| DM2 or DM II | Handwritten and typed problem lists |
| T2DM or T2D | Specialist notes, research papers, discharge summaries |
| DM type 2 | Electronic problem lists that print the full label |
| NIDDM | Older records; non-insulin-dependent diabetes mellitus |
NIDDM has fallen out of favor since plenty of type 2 patients add insulin later on, which makes the old label misleading.
Reading DM2 in a real note
Clinic note: "58 yo M, PMH DM2 on metformin 1000 mg BID, HTN, HLD. A1c 7.4% today, up from 6.9%. Foot exam intact. Plan: diet review, recheck A1c in 3 months." Here DM2 is a long-standing diagnosis, metformin is the medicine, and A1c is the blood test that reflects average sugar over roughly the past few months.
The past history block, labeled PMH, is where DM2 shows up most. Nearby you often see related problems such as HTN (raised blood pressure) and HLD for high cholesterol, since they commonly travel together. The dose in the example is only a sample of how an order is written.
Labs that usually sit beside it
Diagnosis and monitoring lean on a few standard tests. Commonly used cutoffs for diagnosing diabetes are an A1c of about 6.5% or higher, or a fasting glucose of about 126 mg/dL or higher, confirmed on repeat testing. A fasting test may be written FBS for fasting blood sugar.
Ongoing care notes also track kidney function, urine protein, eye exams and foot checks, because long-term high sugar can affect nerves, kidneys, eyes and blood vessels. Labs and medical groups set their own targets and ranges, so the numbers in a given report should be read against that lab's reference values.
When DM2 means myotonic dystrophy type 2
In neuromuscular medicine, DM1 and DM2 name the two types of myotonic dystrophy, an inherited condition that causes muscle stiffness after use (myotonia), weakness, and effects on the heart, eyes and hormones. Type 2 is also called proximal myotonic myopathy and is usually milder than type 1.
Context almost always settles it. A genetics report, a muscle biopsy or a nerve conduction study points to myotonic dystrophy, while sugar readings and diabetes medicines point to diabetes. If a note truly leaves you unsure, a short message to its author will settle the question.
Tips for coders, scribes and students
Coders need the type, any complications and whether insulin or other medicines are used, so a bare DM leads to queries. Writing DM2 or type 2 diabetes along with linked problems, such as kidney disease or nerve damage, gives a complete picture. In ICD-10 coding, type 2 diabetes falls under the E11 category, with further characters for complications.
For neighboring terms on a problem list, browse the conditions and diagnoses hub.
What your own numbers mean and how your diabetes is managed are questions for your primary care clinician, diabetes educator or pharmacist, who know your full history.
Frequently asked questions
What does DM2 mean on my medical record?
In nearly all general medical records it means diabetes mellitus type 2. If the note comes from a muscle or genetics clinic, it may instead mean myotonic dystrophy type 2.
Is DM2 the same as T2DM?
Yes. DM2, DM II, T2DM and T2D are all ways of writing type 2 diabetes mellitus.
What is the difference between DM1 and DM2?
In diabetes care, DM1 is type 1 diabetes, where the body makes little or no insulin, and DM2 is type 2, where the body resists insulin. In neurology, the same letters name the two types of myotonic dystrophy.
Does DM2 mean someone does not take insulin?
No. Many people with type 2 diabetes manage with lifestyle changes and pills, but some also use insulin. That is why the old term NIDDM is no longer preferred.
What is the ICD-10 code family for DM2?
Type 2 diabetes is coded in the E11 category. Additional characters describe complications, and the exact code depends on what the clinician documents.