The BPD medical abbreviation has three common meanings: bronchopulmonary dysplasia, a lung condition in babies born early; borderline personality disorder, a mental health diagnosis; and biparietal diameter, a measurement of a baby's head on a pregnancy ultrasound. The setting of the record is your best guide to the right reading.
A newborn intensive care chart, a psychiatry assessment and an obstetric ultrasound report can each borrow these letters for unrelated ideas. Reading them in the wrong frame can cause real confusion for families. This guide walks through each meaning, shows a sample line from each setting, and lists a fourth, less common meaning from weight loss surgery, so you can match the letters to the right context.
At a glance
Stands for
Bronchopulmonary dysplasia; borderline personality disorder; biparietal diameterLess common meaning
Biliopancreatic diversion, a type of weight loss surgeryWhere each appears
NICU and pediatric lung notes; psychiatry notes; OB ultrasound reportsHow to tell
Patient age, specialty of the note, nearby numbers or unitsSafer to write
The full term the first time it appears in a noteRelated terms
The three main meanings of the BPD medical abbreviation
| Meaning | Setting | Clues in the note |
|---|---|---|
| Bronchopulmonary dysplasia | Neonatal ICU, pediatric lung clinic | Preterm birth, weeks of gestation, oxygen, ventilator |
| Borderline personality disorder | Psychiatry, psychology, primary care | Mood, relationships, therapy, mental status exam |
| Biparietal diameter | Obstetric ultrasound | A measurement in millimeters or centimeters, weeks and days |
| Biliopancreatic diversion | Bariatric surgery | Weight, operative history, vitamin levels |
If none of these clues settles it, the author of the note or the care team can say which they meant.
Bronchopulmonary dysplasia in premature babies
Bronchopulmonary dysplasia is a chronic lung disease that develops in some babies born very early, especially before about 32 weeks. Their lungs are still forming, and the oxygen and breathing support that keep them alive can also injure delicate tissue. The word parts help: broncho refers to the airways, pulmonary to the lungs, and dysplasia to abnormal growth.
Neonatal teams usually diagnose it when a baby still needs extra oxygen or breathing support at a set point, commonly around 36 weeks counted from the mother's last period. Many children improve as their lungs grow, though some need home oxygen, inhaled medicines and close follow up through early childhood. It often follows RDS, respiratory distress syndrome, in the first days of life.
From a pediatric note: "Former 26 wk preemie with BPD, on 1/4 L NC at home." This child was born at 26 weeks and now uses a quarter liter per minute of oxygen through a nasal cannula.
Borderline personality disorder in mental health notes
In psychiatry, BPD stands for borderline personality disorder, a long term pattern that can include intense and shifting emotions, unstable relationships, an unsteady sense of self, impulsive actions and a strong fear of being abandoned. Some people also experience self harm or thoughts of suicide. It is diagnosed by a mental health professional after a careful assessment, not from a single symptom, and it can occur alongside conditions such as MDD, major depressive disorder.
Treatment usually centers on structured talk therapies, such as dialectical behavior therapy, often written DBT. Many people improve a great deal over time. Respectful notes describe the person first, as in a patient with borderline personality disorder. For anyone in the US facing a mental health crisis, calling or texting 988 connects to the Suicide and Crisis Lifeline, day or night.
Biparietal diameter on a pregnancy ultrasound
On an obstetric ultrasound, BPD is a measurement across the widest part of the baby's head, from one side to the other, between the two parietal bones of the skull. It is one of several standard measurements, along with head circumference, abdominal circumference and femur length, used to estimate the age of the pregnancy and the baby's weight.
From an ultrasound report: "BPD 78 mm, consistent with 31w1d. HC, AC and FL concordant." The head width fits a pregnancy of about 31 weeks and 1 day, and the other measurements agree. A report flagging small measurements may lead to a check for IUGR, slowed growth.
A fourth meaning in weight loss surgery
Surgeons may write BPD for biliopancreatic diversion, an operation that reduces stomach size and reroutes part of the small intestine so fewer calories and nutrients are absorbed. A related version adds a duodenal switch and may be written BPD/DS. Because it can lower vitamin and mineral absorption, notes often track levels of iron, calcium, vitamin D and other nutrients for life.
Writing BPD clearly
Since one set of letters points to such different conditions, many educators ask students to spell out the term at first use, especially in referral letters and shared records that cross specialties. A neonatal summary read later by an adult clinic, or a psychiatry history reviewed by a surgeon, is exactly where mix ups happen. You can browse similar shorthand on the diagnosis abbreviations hub.
Here we have outlined what these letters may stand for across specialties. To learn which meaning applies to you or your child, and what it means for care, ask the clinician who wrote the note.
Frequently asked questions
What does BPD mean in medical terms?
BPD can mean bronchopulmonary dysplasia, borderline personality disorder or biparietal diameter. The setting of the note, such as a neonatal unit, a psychiatry visit or a pregnancy scan, tells you which meaning is intended.
What does BPD mean on a pregnancy ultrasound?
On an ultrasound report, BPD means biparietal diameter, the side to side width of the baby's head. It helps estimate how far along the pregnancy is and how the baby is growing.
What does BPD mean for a premature baby?
For a baby born early, BPD usually means bronchopulmonary dysplasia, a chronic lung condition. It is often diagnosed when the baby still needs oxygen or breathing support around 36 weeks after the start of the pregnancy.
Is BPD in a psychiatry note the same as bipolar disorder?
No. In psychiatry BPD means borderline personality disorder. Bipolar disorder is a different condition and is not abbreviated BPD in standard use, though the two are sometimes confused by name.
Why do clinicians still use BPD if it has several meanings?
Within a single specialty the meaning is clear, so it saves time. Problems come when notes cross specialties, so writing the full name is the safer habit.