US Medical Term · anatomy
Bone Marrow
Médula ósea
Where is bone marrow?
The National Cancer Institute (NCI) dictionary describes bone marrow as the soft, spongy tissue that has many blood vessels and is found in the center of most bones. It names two types, red and yellow. Red bone marrow contains blood stem cells that can become red blood cells, white blood cells, or platelets. Yellow bone marrow is made mostly of fat and contains stem cells that can become cartilage, fat, or bone cells.
What does bone marrow do?
MedlinePlus says bone marrow makes different types of blood cells: red blood cells (also called erythrocytes), which carry oxygen from the lungs to every cell in the body; white blood cells (also called leukocytes), which help fight infections; and platelets, which help with blood clotting.
Bone marrow tests named on reports
According to MedlinePlus, bone marrow tests remove a sample of bone marrow and bone, and the sample is usually taken from the back of the hip. Two procedures are used. Bone marrow aspiration removes a small amount of fluid and cells from the bone marrow. Bone marrow biopsy removes a small piece of bone and bone marrow. The two are usually done at the same time. MedlinePlus says the tests are used to help find the cause of too many or too few blood cells, or blood cells that don't look normal.
What it means
Bone marrow is the soft, spongy tissue that has many blood vessels and is found in the center of most bones. There are two types: red and yellow. Red bone marrow contains blood stem cells that can become red blood cells, white blood cells, or platelets; yellow bone marrow is made mostly of fat and contains stem cells that can become cartilage, fat, or bone cells. According to MedlinePlus, bone marrow makes red blood cells, which carry oxygen from the lungs to every cell in the body, white blood cells, which help fight infections, and platelets, which help with blood clotting. Bone marrow tests remove a sample of bone marrow and bone, usually taken from the back of the hip. In Spanish the term is médula ósea.
Bone Marrow in Spanish
- Spanish term
- Médula ósea
- Gender and article
- feminine: la médula ósea
- Pronunciation
- MEH-doo-lah OH-seh-ah
| Other Spanish terms | Where it is used | Note |
|---|---|---|
| médula | General | Short form MedlinePlus en español uses once the context is clear, as in muestras de médula. |
| medular | General | Adjective form: MedlinePlus en español writes aspirado medular for bone marrow aspiration. |
Médula ósea is the term used by both MedlinePlus en español and the National Cancer Institute's Spanish dictionary. It is feminine: la médula ósea. The NCI dictionary names the two types la médula ósea roja and la médula ósea amarilla. Once the context is clear, MedlinePlus en español shortens the term to médula, as in muestras de médula, and it uses the adjective medular in aspirado medular.
MedlinePlus en español titles its test page prueba de la médula ósea and gives examen de la médula ósea as another name. The two procedures are aspirado de médula ósea (bone marrow aspiration) and biopsia de médula ósea (bone marrow biopsy). Blood cell words on the same page are glóbulos rojos, also called eritrocitos; glóbulos blancos, also called leucocitos; and plaquetas. MedlinePlus en español also uses células madre for stem cells and trasplante de médula ósea for bone marrow transplant.
Phrases for an appointment
What a patient or a clinician might say, in English and Spanish:
| Who | English | Spanish |
|---|---|---|
| Clinician | Your blood count results were not normal, so I would like to order a bone marrow test. | Los resultados de su conteo sanguíneo no fueron normales, así que quisiera pedirle una prueba de la médula ósea. |
| Patient | What is bone marrow, and where do you take the sample from? | ¿Qué es la médula ósea y de dónde toman la muestra? |
| Clinician | It is the soft tissue inside the bones. The sample is usually taken from the back of the hip. | Es el tejido suave que está dentro de los huesos. La muestra se suele tomar de la parte posterior de la cadera. |
| Patient | Will I get medicine to help me relax during the bone marrow biopsy? | ¿Me van a dar un medicamento para ayudarme a relajarme durante la biopsia de médula ósea? |
| Clinician | We will do the bone marrow aspiration and the biopsy at the same time. | Vamos a hacerle el aspirado de médula ósea y la biopsia al mismo tiempo. |
| Patient | When will the bone marrow results be ready? | ¿Cuándo van a estar listos los resultados de la médula ósea? |
| Patient | The report says my bone marrow is not making enough blood cells. What does that mean? | El informe dice que mi médula ósea no está produciendo suficientes células sanguíneas. ¿Qué significa eso? |
| Clinician | Has anyone in your family had a bone marrow disease or a bone marrow transplant? | ¿Alguien de su familia ha tenido una enfermedad de la médula ósea o un trasplante de médula ósea? |
In 9 languages
| Language | Term |
|---|---|
| English | Bone Marrow |
| Spanish (Español) | Médula ósea |
| Chinese (中文) | 骨髓 |
| Korean (한국어) | 골수 |
| Vietnamese (Tiếng Việt) | Tủy xương |
| Filipino (Tagalog) | Utak ng buto |
| Portuguese (Português) | Medula óssea |
| Thai (ภาษาไทย) | ไขกระดูก |
| Japanese (日本語) | 骨髄 |
Where you'll see it
Related terms
Your right to an interpreter in the United States
If English is not your primary language and you have difficulty communicating in English, you may need an interpreter or a translated document when you visit a doctor or dentist, go to the emergency room or pick up a prescription. The U.S. Department of Health and Human Services Office for Civil Rights states that two federal laws, Title VI of the Civil Rights Act of 1964 and Section 1557 of the Affordable Care Act, require programs that receive its funding to provide language access services free of charge.
You can ask when you make the appointment or at the front desk: "I need an interpreter, please." «Necesito un intérprete, por favor.»
More terms: Blood and immune system
All terms in this area: Blood and immune system — Sangre y sistema inmunitario
Sources
- bone marrow — NCI Dictionary of Cancer Terms — National Cancer Institute (NCI), NIH
- médula ósea — Diccionario de cáncer del NCI — Instituto Nacional del Cáncer (NCI), NIH
- Bone Marrow Tests — MedlinePlus Medical Tests, National Library of Medicine
- Prueba de la médula ósea — MedlinePlus en español, Biblioteca Nacional de Medicina
- Enfermedades de la médula ósea — MedlinePlus en español, Biblioteca Nacional de Medicina
- Limited English Proficiency (LEP): Your Right to Language Assistance Services — U.S. Department of Health and Human Services, Office for Civil Rights
This page is a language reference. It is not medical advice.
Last reviewed: October 7, 2026