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Short of breath lying flat or waking up breathless

Also called: Orthopnea, paroxysmal nocturnal dyspnea, waking up short of breath

Being short of breath when lying flat, or waking up gasping for air, can be a sign of heart failure, where fluid backs up into the lungs. It can also come from severe lung disease, asthma, or reflux. These symptoms should be checked soon, and sudden severe breathlessness needs 911.

Common causesHeart failure, COPD, asthma, obesity, reflux
Usually serious?Can be
Get checked ifAlways; urgently if severe
If you think it's an emergency, call 911.Thinking about suicide? Call or text 988.

Overview

When you lie flat, more blood returns to the heart. A weak heart can't keep up, so fluid builds in the lungs and makes breathing harder. People often need extra pillows or sleep sitting up.

Paroxysmal nocturnal dyspnea is waking up 1 to 2 hours after falling asleep feeling breathless and needing to sit up or stand. Asthma, COPD, sleep apnea, obesity, and acid reflux can also cause nighttime breathing problems.

When to get medical care

Call 911Severe shortness of breath, gasping, blue lips, or pink frothy phlegm. Shortness of breath with chest pain, fainting, or confusion.
Get care todayNew shortness of breath when lying down. Waking up gasping. Shortness of breath with fast weight gain or leg swelling. Wheezing that doesn't improve with your inhaler.
See a doctor soonNeeding more pillows to breathe. Getting tired or breathless more easily. Swelling in the legs or ankles. Snoring with pauses in breathing.

Causes

Common causes include heart failure, COPD, asthma, obesity, and acid reflux. Other causes include fluid around the lungs, pneumonia, heart valve disease, sleep apnea, weak breathing muscles (diaphragm), and a large belly from ascites or pregnancy.

OwieClear has pages on 2 conditions that can cause short of breath lying flat or waking up breathless. Each shows how soon to get care.

Common causes

  • Heart failureOften needs care today

    The heart doesn't pump as strongly as it should, so fluid can build up.

Less likely causes

What you can do at home

  • Sleep with your head raised on pillows or a wedge.
  • Weigh yourself daily if you have heart failure.
  • Limit salt and follow fluid advice.
  • Use inhalers as prescribed.
  • Don't smoke.

Medicines

Heart failure is treated with water pills and heart medicines. Asthma and COPD are treated with inhalers. Reflux is treated with acid reducers. Some people need oxygen or CPAP.

At the doctor

The provider will check your heart and lungs.

Questions you may be asked

  • How many pillows you use
  • Waking up breathless
  • Leg swelling or weight gain
  • Cough or wheezing
  • Heart or lung disease history

The exam

Listening to the heart and lungs, checking for swelling, and measuring oxygen.

Tests

  • Chest X-ray
  • Echocardiogram
  • ECG
  • BNP blood test
  • Lung function tests

Prevention

You can protect your heart and lungs.

  • Don't smoke
  • Control blood pressure
  • Limit salt
  • Stay active

Check your symptoms

Most symptoms have more than one possible cause. The symptom checker looks at all of your symptoms together, plus your age, and shows how soon to get care.

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Sources

Last updated 2026-11-13.