The c/o medical abbreviation means complains of, and it introduces the symptom a patient describes in their own words. A note that reads pt c/o headache simply says the patient reported a headache.
You will find it in triage notes, nursing assessments, urgent care visits and the opening lines of a physician history. The word complains here has nothing to do with being difficult or unhappy. It is simply the medical abbreviation for complains of, a neutral way to log a symptom.
At a glance
Stands for
Complains of (sometimes complaining of or complaint of)Written as
c/o, C/O, c/o:, occasionally co without the slashWhere you see it
Triage notes, nursing notes, the HPI and discharge summariesUsed with
CC (chief complaint), pt (patient), x (for a length of time)Other meanings
Care of, in mailing addresses; rarely change of in older handwritten notesDo not confuse with
CO (cardiac output, carbon monoxide) and C/F (concern for)
What the C/O medical abbreviation tells a reader
C/O marks the start of a reported symptom. Whatever follows it is something the patient said, not something the clinician measured. That difference matters. A line such as c/o dizziness records a feeling the patient described, while a blood pressure reading or an exam finding comes from the staff member.
Because it points to the patient's own account, c/o usually sits near the top of a note. It often links to the chief complaint, the main reason for the visit, and then the history expands on timing, severity and anything that makes the problem better or worse.
Pt c/o, decoded line by line
A c/o entry rarely travels alone; other shortcuts crowd around it. Below, an emergency department triage entry is taken apart.
| Piece | Plain meaning |
|---|---|
| 45 y/o M | A 45 year old man |
| c/o | Complains of, the patient reports |
| substernal chest pressure | A pressing feeling behind the breastbone |
| x 2 hours | For the past two hours |
| denies SOB | Says he is not short of breath |
The word denies is the mirror image of c/o. It records a symptom the patient was asked about and said they do not have, such as SOB or nausea.
Where the shorthand shows up in real notes
Nurses use c/o in shift notes to capture new symptoms between doctor visits, for example 0300 pt c/o incisional pain 6/10, medicated per order. Physicians use it in the history, scribes type it while the doctor talks, and therapists use it to record pain during a session.
Nursing note: Pt c/o nausea after breakfast, no vomiting, ate 50 percent of tray. Here c/o tells the next nurse that nausea is a new symptom the patient brought up, and the rest of the line gives the context.
Complains of medical abbreviation versus look-alikes
A slash changes a lot in chart shorthand. Several short forms look close to c/o but mean something unrelated.
| Shorthand | Usual meaning | Setting |
|---|---|---|
| c/o | Complains of | History, triage, nursing |
| CO | Cardiac output or carbon monoxide | Critical care, toxicology |
| C/F | Concern for | Assessment and plan |
| C/B | Complicated by | Hospital course |
| H/O | History of | Past history |
| S/P | Status post, after a procedure | Surgical history |
When a slash form is hard to read in handwriting, the safest path is to ask the writer rather than guess from the letters alone.
Tips for students and scribes
Charting teachers often give the same advice about this abbreviation. Put the symptom right after c/o, then add duration with x, location, and severity on a 0 to 10 scale if pain is involved.
The pt c/o medical abbreviation pattern works best when paired with pertinent negatives, the symptoms the patient denies.
Many more of these note shortcuts are gathered on our chart notes and nursing abbreviations page.
If you read c/o in your own records
Seeing that you complained of something can feel odd, but it is neutral wording. It only shows that the clinician wrote down what you told them. If a symptom is listed that you did not report, or the details are wrong, it is reasonable to point that out so the record can be reviewed.
Frequently asked questions
What does pt c/o mean in a medical note?
It means the patient complains of, or reports, the symptom that follows. For example, pt c/o back pain says the patient told staff about back pain. It does not mean the patient was being difficult.
Is c/o the same as chief complaint?
They are close but not identical. The chief complaint, often written CC, is the main reason for the visit. C/O can introduce the chief complaint or any other symptom mentioned during the stay.
Can c/o mean care of in a medical record?
On a mailing address or a form that lists a guardian, c/o can mean care of. Inside a clinical note it almost always means complains of. The surrounding words make the difference clear.
What is the opposite of c/o in charting?
The usual opposite is denies, which records a symptom the patient said they do not have. A complete history often lists both, such as c/o cough, denies fever.