OD
Abbreviation with 8 meanings
| Stands for | Overdose |
|---|---|
| Meanings | 8 |
| Categories | Medical, Education & Academia, Science & Engineering, Business & Finance |
OD has eight meanings. The most common are Overdose (emergency medicine) and Doctor of Optometry (degree); it can also stand for Outside diameter, Oculus dexter (right eye), Omni die (once daily), Optical density and Organization development, plus 1 more listed below.
Meanings of OD at a glance
| # | OD stands for | Context |
|---|---|---|
| 1 | Overdose | Medical › Emergency Medicine |
| 2 | Doctor of Optometry | Education & Academia › Degree |
| 3 | Outside diameter | Science & Engineering › Engineering |
| 4 | Oculus dexter (right eye) | Medical › Medication Route |
| 5 | Omni die (once daily) | Medical › Prescription |
| 6 | Optical density | Science & Engineering › Biology |
| 7 | Organization development | Business & Finance › Human Resources |
| 8 | Overdraft | Business & Finance › Banking |
1. Overdose
Medical · Emergency Medicine Abbreviations
Ingestion, injection or inhalation of a substance in an amount causing toxic effects, intentional or accidental. In emergency records, "OD" commonly refers to opioid, alcohol, stimulant or medication overdose.
Example: Unresponsive, pinpoint pupils, RR 6: suspected opioid OD, naloxone 4 mg IN given.
US drug overdose deaths peaked above 100,000 a year between 2021 and 2023, driven by illicit fentanyl, before declining. Naloxone is available without prescription in the US since 2023. On prescriptions OD means right eye or once daily, both on the ISMP error-prone list, and as a credential it means Doctor of Optometry.
2. Doctor of Optometry
Education & Academia · Degree Abbreviations · also used in medicine
Four-year professional degree for optometrists, who perform eye exams, prescribe glasses and contact lenses and, depending on state law, diagnose and treat many eye diseases with medication. Graduates must pass National Board of Examiners in Optometry (NBEO) exams to be licensed.
Example: Book your annual exam with Dr. Kim, OD, at our Main Street office.
Written O.D. Optometrists differ from ophthalmologists, who are physicians (MD or DO) trained in eye surgery, and from opticians, who fit and dispense eyewear. In medical charts OD is also the Latin "oculus dexter" (right eye), and in general use it means overdose, so context decides.
3. Outside diameter
Science & Engineering · Engineering Abbreviations
Diameter measured across the outer surfaces of a pipe, tube, shaft, bearing or other round part. Tubing is specified by its OD, and fittings, clamps and seals are selected to match it.
Example: Order 25 mm OD stainless tube with a 1.5 mm wall for the handrail.
Pipe is confusing because its nominal size does not equal the OD: a 2-inch NPS steel pipe has an outside diameter of 2.375 inches. Wall thickness is described by schedule, such as Schedule 40. In medicine and biology OD can mean overdose or optical density.
4. Oculus dexter (right eye)
Medical · Medication Route Abbreviations
Ophthalmic abbreviation for the right eye, used in eye-drop orders, eyeglass prescriptions and eye exam records. ISMP lists it as error-prone because OD has been confused with AD (right ear) and with the British "o.d." (once daily), leading to oral drugs being given in the eye.
Example: Latanoprost 0.005% 1 drop OD nightly; IOP 24 OD, 16 OS.
ISMP recommends writing "right eye". Optometry still uses OD and OS on spectacle and contact-lens prescriptions, where the meaning is unambiguous. OD is also the US credential for Doctor of Optometry and common shorthand for "overdose", so context is essential.
5. Omni die (once daily)
Medical · Prescription Abbreviations
British and Commonwealth prescription abbreviation for a single daily dose, still seen on UK, Irish, Indian and Australian scripts. ISMP lists it as error-prone because "OD" also means oculus dexter, the right eye, so oral drugs have been instilled in eyes.
Example: Amlodipine 5 mg OD, review blood pressure in 4 weeks.
Also written o.d. or od. The British National Formulary recommends directions in English without abbreviation, and ISMP advises writing "daily". In US practice OD almost always means right eye, while UK clinicians usually write "R eye" for that, so the abbreviation is ambiguous across borders.
6. Optical density
Science & Engineering · Biology Abbreviations
Measure of how much light a sample absorbs or scatters, read on a spectrophotometer. In microbiology OD600, the reading at 600 nanometers, tracks how many bacteria or yeast cells are growing in a culture, and ELISA plates are read as OD at the substrate's wavelength.
Example: Induce protein expression with IPTG when the culture reaches an OD600 of 0.6.
For dissolved substances, absorbance (A) is the more precise term; OD is used when scattering by cells contributes, as in culture turbidity. The relation between OD and cell number depends on the instrument and organism, so labs calibrate with plate counts. In medicine OD means overdose.
7. Organization development
Business & Finance · Human Resources Abbreviations
Discipline that uses behavioral science to improve how an organization works, through planned change in structure, culture, teamwork, leadership and processes. OD practitioners run engagement surveys, team interventions and change programs.
Example: The OD team facilitated the leadership offsite after the merger.
The field grew in the 1950s and 1960s from Kurt Lewin's research on group dynamics and the "T-group" training developed at the National Training Laboratories. Spelled "organisation development" in British English. Common outside HR meanings include overdose and overdraft.
8. Overdraft
Business & Finance · Banking Abbreviations
Negative balance that occurs when a bank pays a transaction for more than the money available in the account, effectively lending the customer the shortfall. Banks may charge fees or interest, and many offer arranged overdraft limits.
Example: Statement line: OD interest charged on a balance of minus £340 for 12 days.
UK banks offer "arranged" overdrafts with an agreed limit, and since 2020 UK rules have required overdraft charges to be a single annual interest rate rather than fixed daily fees. In the US, overdraft fees, typically around $35 per item, have long been a significant source of bank revenue.
Related abbreviations
More emergency medicine abbreviations
- NEXUS – National Emergency X-Radiography Utilization Study
- NOI – Nature of illness
- NPA – Nasopharyngeal airway
- NRP – Neonatal Resuscitation Program
- OHCA – Out-of-hospital cardiac arrest
- OPA – Oropharyngeal airway
- PALS – Pediatric Advanced Life Support
- PASG – Pneumatic anti-shock garment
See all 97 emergency medicine abbreviations →
More degree abbreviations
- MSW – Master of Social Work
- MTS – Master of Theological Studies
- MUP – Master of Urban Planning
- ND – Doctor of Naturopathic Medicine
- OTD – Doctor of Occupational Therapy
- PGCE – Postgraduate Certificate in Education
- PGCert – Postgraduate Certificate
- PGDip – Postgraduate Diploma
See all 139 degree abbreviations →
This entry is for general education and is not medical advice. Abbreviation use varies between institutions; always confirm in context.