A spitting pot I consider as an essential part of the bed-room apparatus.

That’s what French physician René Laennec wrote in 1821. Laennec, who invented the stethoscope, spent his days gazing at his patients’ phlegm. In the days before x-rays and blood tests, phlegm was considered a valuable diagnostic tool.

Today, most of us don’t carry around a spitting pot. But a persistent question remains, especially during winter, when noses are dripping and chests are rattling.

When you have a cough, should you spit out phlegm or is it better to swallow it?

It might feel like an odd or even slightly stomach-churning topic, but it’s a remarkably common question patients ask doctors.

What is phlegm?

Phlegm, also known as sputum, is the thick, sticky mucus your lungs and windpipe make. This acts as a defensive barrier to protect them.

Its main ingredients are mucins – large, sugar-coated proteins that trap viruses, bacteria, allergens and dust. These mucins also regulate inflammation and the body’s immune response to bacteria and viruses.

We most commonly see phlegm with viral illness during winter. But phlegm is also evident in other medical conditions including asthma and allergies, bacterial infections, such as sinusitis, or with smoking or exposure to air pollution.

In fact, we’re always making phlegm, even when we are healthy. Cells in the lungs secrete mucus to keep surfaces moist and trap irritants. When we encounter something potentially harmful, such as a virus or allergen, immune cells detect the threat and release signals that tell mucus-producing cells to step up their game.

This extra mucus helps trap the invader and move it out of the lungs. Tiny hairs lining the airways (called cilia) then sweep the mucus up to the throat, where we cough it out or swallow it.

The case for spitting

Some people feel better if they spit out phlegm, especially if the phlegm is thick, sticky or irritates the throat.

Spitting also lets you see what’s coming up. If phlegm contains blood, for example, it is important to see a doctor to exclude a more serious underlying illness, such as tuberculosis or cancer.

If you do spit out, do so into a tissue and throw it in the bin. Wash your hands afterwards. This reduces the risk of spreading infection to others via respiratory droplets or contaminated surfaces.

However, spitting out phlegm isn’t always practical, or polite. And for most viral infections, it doesn’t help you get better any faster than swallowing. The aim is to remove phlegm from the lungs, which occurs with either method.

Spitting is also not feasible for young children, who haven’t yet developed the coordination to do so effectively. They’ll generally swallow their phlegm. https://www.youtube.com/embed/WW4skW6gucU?wmode=transparent&start=0 How mucus keeps us healthy all year round, even if we’re not sick.

The case for swallowing

It might not sound particularly appealing, but swallowing phlegm is a normal process, and harmless. In fact, we often swallow phlegm without realising it.

The lungs generate about 50 millilitres of phlegm daily. It goes unnoticed because it’s thin, blends with saliva and we continuously swallow it. We only become aware of it when it thickens, such as during a viral infection.

After you swallow phlegm, it travels to the stomach, where acid and enzymes break it down, along with any germs it carries.

Swallowing phlegm doesn’t “recycle” the germs, and it won’t result in the infection spreading elsewhere.

In fact, swallowing viruses can even help build immunity. Once inside the gut, immune cells begin to recognise pieces of the virus and start preparing the body to respond more effectively to it in the future. Some important immunisations, such as the oral polio vaccine, work through this very mechanism.

So, what’s the verdict?

Whether you spit or swallow phlegm, both are safe. Spitting can help some people feel better, especially if their cough is associated with thick phlegm that’s causing distress.

But for most healthy people, there’s no need to force a cough or spit out phlegm. Swallowing phlegm is completely safe. And in young children, it’s the only feasible option.

In the end, it won’t matter if you spit or swallow your phlegm this winter. So choose what feels right (and least icky) for you.

Niall Johnston, Conjoint Associate Lecturer, Faculty of Medicine, UNSW Sydney and Phoebe Williams, Paediatrician & Infectious Diseases Physician; Senior Lecturer & NHMRC Fellow, Faculty of Medicine, University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

If you Google the terms “constipation” and “heart attack” it’s not long before the name Elvis Presley crops up. Elvis had a longstanding history of chronic constipation and it’s believed he was straining very hard to poo, which then led to a fatal heart attack.

We don’t know what really happened to the so-called King of Rock “n” Roll back in 1977. There were likely several contributing factors to his death, and this theory is one of many.

But after this famous case researchers took a strong interest in the link between constipation and the risk of a heart attack.

This includes a recent study led by Australian researchers involving data from thousands of people.

Are constipation and heart attacks linked?

Large population studies show constipation is linked to an increased risk of heart attacks.

For example, an Australian study involved more than 540,000 people over 60 in hospital for a range of conditions. It found constipated patients had a higher risk of high blood pressure, heart attacks and strokes compared to non-constipated patients of the same age.

A Danish study of more than 900,000 people from hospitals and hospital outpatient clinics also found that people who were constipated had an increased risk of heart attacks and strokes.

It was unclear, however, if this relationship between constipation and an increased risk of heart attacks and strokes would hold true for healthy people outside hospital.

These Australian and Danish studies also did not factor in the effects of drugs used to treat high blood pressure (hypertension), which can make you constipated.

How about this new study?

The recent international study led by Monash University researchers found a connection between constipation and an increased risk of heart attacks, strokes and heart failure in a general population.

The researchers analysed data from the UK Biobank, a database of health-related information from about half a million people in the United Kingdom.

The researchers identified more than 23,000 cases of constipation and accounted for the effect of drugs to treat high blood pressure, which can lead to constipation.

People with constipation (identified through medical records or via a questionnaire) were twice as likely to have a heart attack, stroke or heart failure as those without constipation.

The researchers found a strong link between high blood pressure and constipation. Individuals with hypertension who were also constipated had a 34% increased risk of a major heart event compared to those with just hypertension.

The study only looked at the data from people of European ancestry. However, there is good reason to believe the link between constipation and heart attacks applies to other populations.

A Japanese study looked at more than 45,000 men and women in the general population. It found people passing a bowel motion once every two to three days had a higher risk of dying from heart disease compared with ones who passed at least one bowel motion a day.

How might constipation cause a heart attack?

Chronic constipation can lead to straining when passing a stool. This can result in laboured breathing and can lead to a rise in blood pressure.

In one Japanese study including ten elderly people, blood pressure was high just before passing a bowel motion and continued to rise during the bowel motion. This increase in blood pressure lasted for an hour afterwards, a pattern not seen in younger Japanese people.

One theory is that older people have stiffer blood vessels due to atherosclerosis (thickening or hardening of the arteries caused by a build-up of plaque) and other age-related changes. So their high blood pressure can persist for some time after straining. But the blood pressure of younger people returns quickly to normal as they have more elastic blood vessels.

As blood pressure rises, the risk of heart disease increases. The risk of developing heart disease doubles when systolic blood pressure (the top number in your blood pressure reading) rises permanently by 20 mmHg (millimetres of mercury, a standard measure of blood pressure).

The systolic blood pressure rise with straining in passing a stool has been reported to be as high as 70 mmHg. This rise is only temporary but with persistent straining in chronic constipation this could lead to an increased risk of heart attacks.

Some people with chronic constipation may have an impaired function of their vagus nerve, which controls various bodily functions, including digestion, heart rate and breathing.

This impaired function can result in abnormalities of heart rate and over-activation of the flight-fight response. This can, in turn, lead to elevated blood pressure.

Another intriguing avenue of research examines the imbalance in gut bacteria in people with constipation.

This imbalance, known as dysbiosis, can result in microbes and other substances leaking through the gut barrier into the bloodstream and triggering an immune response. This, in turn, can lead to low-grade inflammation in the blood circulation and arteries becoming stiffer, increasing the risk of a heart attack.

This latest study also explored genetic links between constipation and heart disease. The researchers found shared genetic factors that underlie both constipation and heart disease.

What can we do about this?

Constipation affects around 19% of the global population aged 60 and older. So there is a substantial portion of the population at an increased risk of heart disease due to their bowel health.

Managing chronic constipation through dietary changes (particularly increased dietary fibre), increased physical activity, ensuring adequate hydration and using medications, if necessary, are all important ways to help improve bowel function and reduce the risk of heart disease.

Vincent Ho, Associate Professor and clinical academic gastroenterologist, Western Sydney University

This article is republished from The Conversation under a Creative Commons license. Read the original article.