The Science Behind the Death Rattle

Many families are startled by it: a wet, rattling sound in the breathing of someone who is near death. It is often called the death rattle. It can be hard to hear, but it is common, and researchers have studied it closely. This article explains what they have found. It is general information, not medical advice.

What is the death rattle?

The sound of fluid in the throat. A palliative care review in BMJ Supportive & Palliative Care explains that it is caused by saliva pooling at the back of the throat. This happens in people who cannot swallow, usually in the last days of life. Alberta Health Services describes it as turbulent airflow over retained secretions in the throat and airways.

How common is it?

Common, but it varies a lot. A systematic review of 39 studies found reported rates from 12 to 92 percent, with a weighted average of 35 percent.

Does it hurt the dying person?

Probably not. The same review concludes that death rattle is a rather common symptom, but it is doubtful that patients suffer from it. Alberta Health Services says patients are generally unaware of it because of their level of consciousness, while family members are often distressed. A summary in Canadian Family Physician agrees that it may not distress patients but may distress family and caregivers. Virtual Hospice advises care teams to explain to families that an unresponsive patient is not aware of the secretions.

How long before death does it start?

Usually within a day or two. Virtual Hospice reports that the median time from the start of death rattle until death is between 11 and 28 hours. CareSearch notes that noisy breathing usually occurs when the person has a reduced level of consciousness, and indicates that death is expected within days.

What can help?

Mostly reassurance and comfort. Alberta Health Services says the key step is to reassure the family and explain that the sound does not mean the person is in respiratory distress. Gentle repositioning can help. Virtual Hospice says deep suctioning can be distressing and may cause more secretions, so it should be avoided unless secretions are visible in the mouth.

Do medicines work?

Not clearly. The systematic review found no evidence that any antimuscarinic drug was better than no treatment, and Alberta Health Services says no drug treatment has been found superior to placebo. A 2021 trial in JAMA, summarized by Canadian Family Physician, gave 162 hospice patients in their final days either a drug called scopolamine butylbromide or a placebo before any rattle appeared. Death rattle developed in 13 percent of those given the drug and 27 percent of those given the placebo. Alberta Health Services also says there is no evidence that withholding fluids or giving diuretics reduces secretions.

What can families do?

Tell the care team what you notice and ask what to expect. For more, see What to Expect in the Final Hours, Does Dying Hurt?, and Comfort Care Explained.