Paroxysmal nocturnal dyspnea (PND) causes sudden shortness of breath during sleep. As a result, you wake up gasping for air. It tends to occur within a few hours after you’ve fallen asleep.
The condition can also be defined by the meaning of its name:
- “Paroxysmal” describes an episode of symptoms that appear suddenly and may reoccur.
- “Nocturnal” refers to nighttime.
- “Dyspnea” is a medical term that refers to shortness of breath, breathlessness, or uncomfortable breathing.
Dyspnea can occur at any time of the day or night. It’s a potential symptom of a number of serious respiratory and circulatory diseases, including:
Read on to find out what health conditions can cause PND, and how it’s treated.
PND is a symptom that can be caused by a number of different respiratory and circulatory conditions. Sleep apnea, most commonly obstructive sleep apnea, on the other hand, is a medical condition on its own. Sleep apnea can cause PND, but not vice versa.
People who have sleep apnea experience multiple episodes of slowed or stopped breathing during the night. Sometimes breathing is interrupted for long enough to cause PND and wake you up.
In obstructive sleep apnea, breathing slows or stops altogether because of a physical tissue obstruction to the upper airway. In central sleep apnea, breathing slows or stops altogether because the brain doesn’t send the signals required to breathe properly.
Both types of sleep apnea can cause PND. However, not all cases of PND are caused by sleep apnea.
PND tends to occur within a few hours after you’ve fallen asleep. It wakes you up. You might gasp for air, cough, or sit or stand up to try to open your airways. After a while, your breathing may return to normal. It might take a half an hour, or sometimes longer, to recover.
Many people find it difficult to return to sleep after an episode of PND. PND can be distressing, and one or more episodes may lead to sleep anxiety or even insomnia.
If sitting or standing up doesn’t relieve symptoms of PND, you should call for emergency medical assistance right away.
There is a lack of consensus over the term “paroxysmal nocturnal dyspnea.” Some medical professionals use it to refer exclusively to a symptom of heart failure. In other cases, it’s used to describe nighttime shortness of breath caused by other medical conditions, some of which are benign.
Some of the most common causes of nighttime shortness of breath are described below.
Heart failure, also known as congestive heart failure, occurs when the heart muscle struggles to adequately pump blood throughout the body. It can lead to fluid buildup in the lungs (pulmonary edema) and around the lungs, which can make it difficult to breathe. Many people with heart failure also experience difficulty breathing when exerting themselves or laying down.
PND can also be related to lung and respiratory system function. Respiratory conditions that can cause or lead to PND include:
- postnasal drip
- pulmonary edema
- sleep apnea
- pulmonary artery embolism
- restrictive lung disease
Other medical conditions
PND can also be related to a variety of other conditions. Some of these include:
- stomach acid reflux
- kidney failure
- anxiety or panic attacks
PND is serious. You should see a doctor to determine what’s causing your nighttime shortness of breath.
Your doctor will try to determine the underlying cause of your PND. They’ll ask you about your medical history and symptoms, and conduct tests to assess your heart and lungs.
Diagnostic tests can include one or more of the following:
- blood tests
- chest CT scan
- chest X-ray
- coronary artery angiogram
- echocardiogram, or a cardiac ultrasound
- 12-lead electrocardiogram
- chest MRI scan
- pulmonary function test (spirometry testing)
- cardiac stress test
Treatments for PND vary depending on the cause. Your doctor can help you understand the best course of treatment based on your symptoms.
For people whose PND is caused by heart failure, a number of treatments may improve symptoms. Medical treatment can include diuretic therapy to reduce fluid retention and cardiac medication therapy to protect the heart or reduce blood pressure or heart rate. Other treatments, including surgery, may help to decrease the workload on the heart and provide the cells with additional oxygen. Sleeping propped up on several pillows may also provide relief from PND.
When PND is caused by a lung or other respiratory system disorder, treating the disorder usually helps to ease symptoms. For instance, long-term asthma control medications can help to reduce shortness of breath at night. In cases of sleep apnea, a continuous positive airway pressure (CPAP) machine, possibly with added supplemental oxygen, may help to improve breathing.
Stomach acid reflux is treatable with lifestyle changes and antacids.
Other treatments focus on reducing stress and improving the overall quality of your sleep. Avoiding caffeine and alcohol before bed and adopting a regular sleep schedule are just a few things you can do to improve the overall quality of your sleep.
Heart failure is one of the most serious causes of PND. The outlook for heart failure depends on the underlying cause, as well as risk factors, lifestyle, and treatments. The course of the disease varies a lot from one person to the next. Heart failure is typically long term and usually gets worse over time, but a number of available treatments can slow its progression and help to prevent acute decompensatory episodes.
Other conditions that cause PND, such as asthma, stomach acid reflux, or sleep apnea, are generally highly treatable. If you experience PND, you should make an appointment with a doctor to identify or confirm the cause.
In addition, remember to seek emergency medical attention if you experience severe or ongoing shortness of breath or chest pain.