Circulation & Breathing
Shortness of Breath in Pregnancy
Feeling breathless is common from mid-pregnancy as your body and bump change how you breathe — but sudden, severe breathlessness always needs urgent care.
Written and fact-checked by the ParentVibes editorial team against WHO, NHS, ACOG and peer-reviewed guidance. Not yet reviewed by a named clinician.
Quick facts
- When it's common
- From the second trimester onwards
- Usual pattern
- Breathless on exertion, eases with rest
- Main causes
- Progesterone and a growing uterus
- Emergency signs
- Sudden, severe, or breathlessness at rest
- Also urgent
- Chest pain, fast heartbeat, blue lips, coughing blood
Finding yourself puffing after a flight of stairs, or simply feeling like you can't take a full deep breath, is a very common experience from around the second trimester onwards. It can feel alarming, but in most cases it's a predictable result of the way your body and growing baby change your breathing.
That said, breathing is one area where it really is worth knowing the difference between 'pregnancy normal' and 'needs checking now'. This guide explains why breathlessness happens, what's expected, and the signs — like sudden or severe breathlessness, chest pain or a racing heart — that mean you should seek emergency care straight away.
What is shortness of breath in pregnancy?
Shortness of breath, or breathlessness, in pregnancy is the sensation of not being able to get quite enough air, or having to work harder to breathe than before you were pregnant. It commonly starts around the second trimester and often becomes more noticeable in the third, as your uterus grows and pushes upward against your diaphragm, leaving less room for your lungs to fully expand.
Hormonal changes play a part too — rising progesterone increases your drive to breathe, so you naturally take in more air with each breath, which can itself feel like breathlessness even though it's simply a more efficient way of getting oxygen to your baby. For most people, mild breathlessness on exertion — climbing stairs, walking briskly, bending down — that settles with rest is a normal, if uncomfortable, feature of later pregnancy.
A little relief before labour
Many people notice breathing gets slightly easier in the final weeks once the baby's head engages ('drops') into the pelvis, taking some pressure off the diaphragm — though this varies and isn't guaranteed before labour starts.
What causes shortness of breath in pregnancy?
Breathlessness in pregnancy is usually explained by normal physical and hormonal changes:
Your growing uterus
As your baby and uterus grow, especially from the second trimester, they push upward on your diaphragm, reducing the space your lungs have to expand fully.
Rising progesterone
This hormone stimulates your breathing centre, making you breathe a little faster and more deeply even at rest — an efficient way to get more oxygen to your baby, but one that can feel like breathlessness.
Increased oxygen demand
Your body needs more oxygen to support your baby, the placenta and your own increased blood volume, so your heart and lungs both work harder.
Anaemia
Low iron reduces the oxygen-carrying capacity of your blood, which can make you feel more breathless than expected, often alongside tiredness.
Weight gain and reduced fitness
Carrying extra weight and doing less vigorous exercise as pregnancy progresses can make everyday activities feel more breath-taking.
Nasal congestion
Pregnancy can swell the lining of your nose and airways, making breathing feel more restricted, particularly at night.
More likely if…
- You're carrying twins or more
- You already have asthma or another lung condition
- You're carrying extra weight
- You have iron-deficiency anaemia
When shortness of breath is normal
Mild breathlessness with exertion is expected for many people from the second trimester. These patterns are reassuring:
- Breathlessness that comes on with activity — stairs, walking briskly, bending — and eases within a few minutes of resting.
- You can still speak in full sentences without gasping for air.
- No chest pain, blue lips, or feeling that your heart is racing uncontrollably.
- It develops gradually over weeks as your bump grows, rather than appearing suddenly.
| Usually normal breathlessness | Needs emergency care | |
|---|---|---|
| Onset | Gradual, from mid-pregnancy | Sudden, or comes on rapidly |
| Trigger | With exertion; eases with rest | At rest, or not improving with rest |
| Speaking | You can talk normally | Gasping, can't finish sentences |
| Other signs | None, or mild fatigue | Chest pain, fast heartbeat, blue lips, coughing blood |
Sitting up can help
If you feel breathless while lying down, propping yourself up with extra pillows can ease the pressure on your diaphragm and lungs.
Warning signs — get emergency help now
Occasionally breathlessness signals a serious problem such as a blood clot in the lung (pulmonary embolism) or a heart problem. Call your emergency number or go to your nearest emergency department immediately if you have:
Seek urgent medical care if you have
- Sudden or severe breathlessness that comes on quickly.
- Breathlessness at rest, or that doesn't ease when you stop and rest.
- Chest pain, especially if it's sharp or worse when you breathe in.
- A fast or pounding heartbeat alongside breathlessness.
- Coughing up blood.
- Blue or grey-tinged lips, face or fingertips.
- Breathlessness with wheeze, if you have asthma and your usual reliever isn't helping.
If you ever notice your baby's movements have reduced or stopped, contact your maternity unit the same day as well.
This needs immediate care
Sudden, severe breathlessness — especially with chest pain, a fast heart rate or coughing blood — can be a sign of a pulmonary embolism (a blood clot on the lung), which is more common in pregnancy and needs emergency treatment. Do not wait to see if it passes.
Self-care & easing breathlessness
You can't stop your body needing more oxygen, but these steps can make mild, normal breathlessness more comfortable:
Adjust your posture
- Sit and stand as tall as you can to give your lungs more room.
- Prop yourself up with pillows when lying down or sleeping.
- Avoid slouching, which compresses your chest and lungs further.
Pace your activity
- Slow down and take breaks during exercise or exertion.
- Climb stairs at a gentle pace, pausing if needed.
- Avoid pushing through breathlessness — rest until it settles.
Manage triggers
- Avoid smoky or heavily polluted environments.
- Treat nasal congestion with a saline spray if needed, checking with your pharmacist first.
- Stay active with gentle, doctor-approved exercise to support your fitness.
Keep moving gently
Regular, gentle activity like walking or swimming, as approved by your midwife, can actually improve how breathless you feel over time by supporting your fitness and circulation.
When to consult a doctor
Book a non-urgent appointment with your doctor or midwife if:
- Breathlessness is worsening steadily rather than staying stable.
- It's interfering with your ability to do normal daily activities.
- You have a history of asthma or another lung or heart condition.
- You feel breathless alongside ongoing tiredness or pale skin (possible anaemia).
- You're simply unsure whether what you're feeling is 'normal' for your stage of pregnancy.
Track how your breathing changes
Noting when breathlessness happens and how severe it feels helps your midwife assess it accurately at your next appointment.
Open the Pregnancy TrackerFrequently asked questions
Is shortness of breath normal in pregnancy?
Mild breathlessness with exertion is common from the second trimester onwards, caused by rising progesterone and your growing uterus pressing on your diaphragm. It should ease with rest.
Why does pregnancy make me breathe faster even at rest?
Rising progesterone increases your drive to breathe, so you naturally take deeper, more frequent breaths — an efficient way of getting more oxygen to your baby, but one that can feel like breathlessness.
Will breathlessness get better before I give birth?
For some people it eases once the baby's head engages in the pelvis in the final weeks, taking pressure off the diaphragm — but this varies, and doesn't happen for everyone before labour begins.
Can shortness of breath be a sign of a blood clot?
Yes, if it's sudden or severe and comes with chest pain, a fast heartbeat or coughing up blood. Pregnancy increases the risk of blood clots, so these combinations need emergency care.
I have asthma — how do I tell pregnancy breathlessness from a flare-up?
It can be difficult to distinguish. Contact your doctor or midwife if your usual reliever inhaler isn't helping, or if breathlessness comes with wheeze, as this needs prompt assessment.
When should I go to A&E for breathlessness in pregnancy?
Seek emergency care for breathlessness that's sudden or severe, happens at rest, or comes with chest pain, a fast heartbeat, coughing up blood, or blue-tinged lips.
Your next steps
Track your pregnancy
Log symptoms week by week, get personalised tips, and see how your pregnancy is progressing.
Open Pregnancy TrackerPregnancy week-by-week
Follow your baby's growth and your body's changes from week 1 to 40 in plain language.
Explore the guideFind a gynaecologist
Have a personal concern? Book with a trusted obstetrician or gynaecologist near you.
Find a doctorRelated pregnancy symptoms
Helpful resources
Sources
- NHS — Pregnancy: common symptoms & concerns
- ACOG — Pregnancy resources (American College of Obstetricians and Gynecologists)
- WHO — Maternal health & pregnancy care
- NHS — Shortness of breath
Next review due: 6 January 2027.
Medical disclaimer
This page is general information about a common pregnancy symptom and does not replace personal medical advice. Every pregnancy is different. If you have severe pain, heavy bleeding, a bad headache with vision changes, reduced or absent baby movements, breathing difficulty, fever, or you feel something is seriously wrong, contact your doctor or midwife or go to your nearest emergency department straight away. When in doubt, always get checked — it is never a waste of anyone's time.
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