Key Takeaways
Mild breathlessness can start early in pregnancy as breathing and circulation change.
Symptoms should not automatically be attributed to pregnancy, especially when they are new, persistent, or worsening.
Sudden or severe difficulty breathing, chest pain, fainting, or trouble speaking because of breathlessness calls for emergency care.
A prenatal clinician can help to assess for other causes, including anemia, asthma, infection, blood clots, and heart or blood-pressure conditions.
Slowing down and changing position may help mild symptoms, but these steps cannot treat a serious cause.
Mild shortness of breath during pregnancy can happen even when the lungs and heart are healthy. Hormonal changes affect breathing early on, while later changes in physical demand and the position of the diaphragm can make breathing feel less comfortable. But a major change in breathing, breathlessness at rest, or symptoms that keep getting worse need medical attention.
If you are struggling to breathe, have chest pain, feel faint, or cannot speak comfortably because you are short of breath, seek emergency medical care now. Otherwise, the sections below can help you recognize common patterns and decide when to contact your prenatal care team.
Is Shortness of Breath Normal During Pregnancy?
Mild breathlessness can be a normal response to pregnancy. You may notice that climbing stairs takes more effort or that you want to take a deeper breath while talking. Symptoms are often gradual, improve with rest, and are not accompanied by chest pain, fainting, or other warning signs. This pattern is not a diagnosis, however. New or persistent symptoms deserve a conversation with your clinician.
The American College of Obstetricians and Gynecologists (ACOG) notes that breathlessness can start early, even before the growing uterus places substantial pressure on the diaphragm. ACOG also advises contacting an OB/GYN when there is a major change in breathing or associated concerning symptoms.
Why Does Pregnancy Cause Shortness of Breath?
Pregnancy changes how the body moves air and circulates blood. Progesterone increases the drive to breathe, so people often take deeper breaths without necessarily breathing faster. At the same time, oxygen needs and the workload of the heart increase. That combination can create a sensation of not getting quite enough air even when oxygen levels are normal.
Later, as the uterus grows, the diaphragm sits higher in the chest. Your body adapts to this change, but certain movements and positions may feel more tiring. The uterus is not the only explanation: breathlessness may appear during the first trimester, well before abdominal size becomes a significant factor.
Shortness of Breath by Trimester
First Trimester
Hormonal changes can alter the sensation of breathing early in pregnancy. Some people notice needing deeper breaths during otherwise ordinary activities. New breathlessness that is marked, persistent, or associated with illness should still be assessed.
Second Trimester
As circulation and activity demands change, breathlessness may become more noticeable. This is also a time when anemia or a respiratory condition may contribute, particularly if symptoms appear with unusual fatigue, weakness, wheezing, or dizziness.
Third Trimester
An enlarged uterus can change the diaphragm’s resting position and make bending, climbing stairs, or lying in some positions less comfortable. Symptoms may fluctuate rather than follow a predictable week-by-week timeline. Breathlessness at rest or new difficulty lying flat should not simply be blamed on late pregnancy.
Other Causes of Shortness of Breath During Pregnancy
Not every episode of breathlessness is caused by normal pregnancy physiology. Several conditions can require testing or treatment.
Iron-Deficiency Anemia
Anemia means there are too few healthy red blood cells, or too little hemoglobin, to carry oxygen effectively. Iron-deficiency anemia may cause fatigue, weakness, dizziness, and shortness of breath. A clinician can check blood tests and determine whether iron treatment is appropriate. Do not start high-dose iron based on breathlessness alone.
Asthma and Respiratory Infections
Asthma may cause breathlessness with wheezing, coughing, or chest tightness. Pregnancy can affect asthma control, so report any worsening symptoms and continue prescribed medications unless your treating clinician advises otherwise. Respiratory infections, including influenza, COVID-19, and pneumonia, may also cause cough, fever, and breathing difficulty. Shortness of breath with significant illness warrants prompt evaluation.
Preeclampsia and High Blood Pressure
Preeclampsia is a pregnancy-related hypertensive disorder that usually develops after 20 weeks, although related complications can also occur after delivery. In severe cases, fluid can collect in the lungs and cause breathing difficulty. Severe or persistent headache, vision changes, pain in the upper abdomen, and sudden marked swelling are additional warning signs. Do not try to diagnose preeclampsia at home.
Blood Clots and Pulmonary Embolism
Pregnancy raises the risk of blood clots. A pulmonary embolism occurs when a clot blocks blood flow in the lungs. Possible warning signs include sudden unexplained breathlessness, chest pain, rapid heartbeat, fainting, coughing blood, or pain and swelling in one leg. This is an emergency and must not be evaluated using home tests.
Heart Conditions
A preexisting heart condition, an abnormal heart rhythm, or a pregnancy-associated heart problem may contribute to significant breathlessness. Peripartum cardiomyopathy is an uncommon form of heart muscle weakness that can appear late in pregnancy or after birth. New difficulty breathing while lying flat, swelling with breathing trouble, fainting, or a racing heartbeat calls for urgent assessment.
How to Relieve Mild Shortness of Breath During Pregnancy
For mild, familiar breathlessness without warning signs, simple adjustments may make daily activities more comfortable:
Slow your pace and take breaks before you become exhausted.
Sitting upright or adjusting your posture when bending or reclining feels uncomfortable.
Rest in a position that makes breathing easier; side-lying may be more comfortable later in pregnancy.
Drink fluids regularly and avoid exercising in excessive heat.
Choose an activity level that fits your health and pregnancy, and discuss changes with your prenatal clinician.
Stop exercising if you experience unusual breathlessness, dizziness, chest pain, or other concerning symptoms. ACOG lists shortness of breath before starting exercise as a reason to stop and call your OB/GYN. Never push through serious breathing difficulty or rely on breathing exercises to postpone evaluation.
When Is Shortness of Breath During Pregnancy a Warning Sign?
Breathing symptoms need attention when they are new, do not settle, are getting worse, or occur alongside other symptoms. The most important question is not simply which trimester you are in, but how your breathing has changed and whether there are warning signs.
Seek emergency medical care now if you have:
Sudden or severe difficulty breathing, or breathlessness that makes speaking difficult.
Breathing trouble with chest pain or pressure, fainting, or a very fast or irregular heartbeat.
Sudden breathlessness with one-sided leg pain or swelling, or coughing blood.
Blue or gray lips or skin, severe weakness, or rapidly worsening symptoms.
Significant breathing difficulty when lying flat, especially with swelling or chest symptoms.
Contact your prenatal provider promptly if you notice:
New, persistent, or worsening breathlessness, even without a dramatic emergency symptom.
Breathlessness with unusual fatigue, dizziness, cough, fever, or wheezing.
Breathlessness with a severe headache, vision changes, sudden swelling, or upper abdominal pain.
The CDC urgent maternal warning signs include trouble breathing, chest pain, dizziness or fainting, a fast-beating heart, severe headache, vision changes, and severe swelling. Such symptoms can occur during pregnancy or after delivery. If symptoms are severe or you cannot quickly reach a clinician, go to the emergency department or call emergency services.
Quick Guide: What Your Breathing Symptoms May Mean
| Situation | Possible Explanation | Next Step |
|---|---|---|
| Mild, gradual breathlessness with activity that settles with rest | May reflect pregnancy-related changes | Mention it at your prenatal visit; call sooner if new or changing |
| New or progressively worsening breathlessness | Normal changes or another medical condition | Contact your prenatal clinician promptly |
| Breathlessness with fatigue, dizziness, or weakness | Anemia or another condition may contribute | Arrange medical assessment and any recommended testing |
| Sudden severe breathlessness or chest pain | Possible serious lung or heart problem | Seek emergency care now |
| Breathlessness with severe headache, vision change, or marked swelling | Possible pregnancy complication | Seek urgent medical evaluation; emergency care if severe |
How Your Prenatal Care Provider May Evaluate Breathlessness
Your clinician may ask when symptoms started, whether they occur at rest or with activity, and whether you have pain, cough, fever, swelling, or a history of asthma or heart disease. An exam may include blood pressure, heart rate, oxygen level, and heart and lung assessment. Depending on the findings, blood tests for anemia or additional testing may be appropriate.
Consistent prenatal care helps identify conditions such as anemia or high blood pressure and creates opportunities to discuss new symptoms. If you are preparing for an early visit, Enrich Health also explains what to expect at your first OB/GYN appointment.
Prenatal Care at Enrich Health
Enrich Health offers prenatal care in Connecticut and group prenatal care through Motherhood Circles. Visits are a place to discuss symptoms, ask questions, and work with your care team on appropriate next steps. For readers interested in additional education, the practice also offers pregnancy wellness classes.
Breathing difficulty that is severe or sudden needs emergency medical care rather than an appointment request. For routine prenatal questions or to discuss establishing care, contact Enrich Health.
Contact Enrich Health to ask about prenatal services.
Frequently Asked Questions
How early can shortness of breath begin in pregnancy?
Breathlessness can begin in the first trimester. Progesterone changes the way the body regulates breathing before the uterus becomes large enough to change the diaphragm’s position significantly. Mild breathlessness may be related to these changes, but new, persistent, or worsening symptoms should be discussed with a prenatal clinician.
Why is breathing harder in the third trimester?
By the third trimester, the enlarged uterus shifts the diaphragm upward, and everyday activities can require more effort. However, a sudden change in breathing, breathlessness at rest, or trouble lying flat should not be assumed to be a normal late-pregnancy symptom.
Can anemia make you short of breath while pregnant?
Yes. Iron-deficiency anemia may contribute to fatigue, dizziness, weakness, and shortness of breath because hemoglobin helps carry oxygen through the body. Symptoms alone cannot confirm anemia. A healthcare professional can assess your symptoms and recommend testing or treatment if needed.
Should I call my OB/GYN if I feel short of breath?
Call if shortness of breath is new, persistent, worsening, or accompanied by other symptoms. Sudden or severe trouble breathing, chest pain, fainting, or inability to speak comfortably due to breathlessness requires emergency care. You do not need to wait for your next scheduled visit to raise a concern.
Can shortness of breath be a sign of preeclampsia?
It can, particularly when severe preeclampsia causes fluid buildup in the lungs. Severe headache, vision changes, upper abdominal pain, or marked swelling can be associated with warning signs. Breathing trouble or a combination of concerning symptoms needs prompt medical assessment, not home monitoring alone.
