US Medical Term · anatomy
Diaphragm
Diafragma
Where is the diaphragm?
The National Cancer Institute (NCI) dictionary defines the diaphragm as the thin muscle below the lungs and heart that separates the chest from the abdomen. The NCI's drawing of the respiratory system shows the diaphragm together with the trachea, the right and left lungs and their lobes, the bronchi and the lymph nodes.
What does the diaphragm do in breathing?
According to the National Heart, Lung, and Blood Institute (NHLBI), when you breathe in, or inhale, your diaphragm contracts and moves downward. This increases the space in the chest cavity, the lungs expand into it, and air is sucked in through the nose or mouth. When you breathe out, or exhale, the diaphragm and rib muscles relax, the chest cavity gets smaller and the lungs deflate. The NHLBI adds that breathing out requires no effort from the body unless a person has a lung disease or is doing physical activity.
What it means
The diaphragm is the thin muscle below the lungs and heart that separates the chest from the abdomen. It takes part in breathing: according to the National Heart, Lung, and Blood Institute, when a person breathes in, the diaphragm contracts and moves downward, which increases the space in the chest cavity, and the lungs expand into it. When a person breathes out, the diaphragm and rib muscles relax, reducing the space in the chest cavity, and the lungs deflate. The muscles between the ribs also help enlarge the chest cavity. This page is about the muscle. The Spanish word is diafragma, and the Spanish dictionary also gives that word a second sense, a contraceptive device.
Diaphragm in Spanish
- Spanish term
- Diafragma
- Gender and article
- masculine: el diafragma
- Pronunciation
- dyah-FRAHG-mah
Diafragma is the headword in the National Cancer Institute's Spanish dictionary, which defines it as a thin muscle located below the lungs and the heart that separates the tórax from the abdomen. The Spanish dictionary marks diafragma as a masculine noun, so the article is el: el diafragma. Its first sense is the membrane, formed mostly of muscle fibres, that separates the thoracic cavity from the abdominal cavity in the body of mammals.
The dictionary's second sense of diafragma is a contraceptive device, a flexible disc placed at the back of the vagina, and a further sense is the part of a camera lens that regulates the amount of light let through, so context shows which one is meant. In the Spanish breathing explanation from the National Heart, Lung, and Blood Institute, the diaphragm se contrae (contracts) on inhalación (breathing in) and relaxes on exhalación (breathing out), and the chest cavity is the cavidad torácica.
Phrases for an appointment
What a patient or a clinician might say, in English and Spanish:
| Who | English | Spanish |
|---|---|---|
| Clinician | Take a deep breath in and hold it. | Respire profundo y aguante la respiración. |
| Patient | It hurts just below my ribs when I breathe in deeply. | Me duele justo debajo de las costillas cuando respiro profundo. |
| Clinician | The diaphragm is the muscle that separates your chest from your abdomen. | El diafragma es el músculo que separa el tórax del abdomen. |
| Patient | The report mentions my diaphragm. Is that the muscle for breathing? | El informe menciona el diafragma. ¿Es el músculo de la respiración? |
| Clinician | Yes. When you breathe in, the diaphragm contracts and moves downward. | Sí. Al inhalar, el diafragma se contrae y se mueve hacia abajo. |
| Patient | I have had hiccups for two days and they will not stop. | Llevo dos días con hipo y no se me quita. |
| Clinician | We are going to take a chest X-ray to look at your lungs and diaphragm. | Vamos a hacerle una radiografía de tórax para ver los pulmones y el diafragma. |
| Patient | My doctor said part of my stomach is pushing up through the diaphragm. | Mi médico dijo que parte del estómago está pasando hacia arriba a través del diafragma. |
In 9 languages
| Language | Term |
|---|---|
| English | Diaphragm |
| Spanish (Español) | Diafragma |
| Chinese (中文) | 橫膈膜 |
| Korean (한국어) | 횡격막 |
| Vietnamese (Tiếng Việt) | Cơ hoành |
| Filipino (Tagalog) | Dayapragma |
| Portuguese (Português) | Diafragma |
| Thai (ภาษาไทย) | กระบังลม |
| Japanese (日本語) | 横隔膜 |
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: Reproductive health and pregnancy
All terms in this area: Reproductive health and pregnancy — Salud reproductiva y embarazo
Sources
- diaphragm — NCI Dictionary of Cancer Terms — National Cancer Institute (NCI), NIH
- diafragma — Diccionario de cáncer del NCI — Instituto Nacional del Cáncer (NCI), NIH
- How the Lungs Work - What Breathing Does for the Body — National Heart, Lung, and Blood Institute (NHLBI), NIH
- Cómo funcionan los pulmones - Qué hace la respiración por el cuerpo — Instituto Nacional del Corazón, los Pulmones y la Sangre (NHLBI), NIH
- diafragma — Diccionario de la lengua española — Real Academia Española / ASALE
- 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 8, 2026