4. Sudden Nighttime Breathlessness (Paroxysmal Nocturnal Dyspnea – PND)
Paroxysmal nocturnal dyspnea (PND) is a dramatic and frightening symptom of heart failure. It refers to waking up suddenly at night, gasping for breath. Unlike orthopnea, where breathlessness appears when lying flat, PND wakes a person from sleep, often after one to two hours. Patients may sit up, dangle their legs, or rush to a window for air.
This occurs because, during sleep, fluid from the legs moves into circulation and eventually into the lungs, causing congestion.
For example, Mr. George, a 72-year-old shopkeeper, recalled waking up several nights in a row gasping for air. He said it felt like “drowning in my own body.” His wife described how he would sit upright, sweating and panicked, until the feeling passed. This frightening pattern led him to seek medical care, where he was diagnosed with heart failure. After starting medication, these episodes decreased.
PND is emotionally distressing. Many patients develop anxiety, fearing they will not wake up the next time. Families may also panic when witnessing these episodes. Recognizing PND is vital, as it almost always indicates significant heart failure and requires medical intervention.