A persistent cough can be embarrassing, especially if people think you have COVID.

Coughing frequently can also make you physically tired, interfere with sleep and trigger urinary incontinence. As a GP, I have even treated patients whose repetitive forceful coughing has caused stress fractures in their ribs.

So, why do some coughs linger so long? Here are some of the most common causes – and signs you should get checked for something more serious.

Why do we cough?

The cough reflex is an important protective mechanism. Forcefully expelling air helps clear our lungs and keep them safe from irritants, infections and the risk of choking.

Some people who have long-term conditions, such as chronic bronchitis or bronchiectasis, have to cough frequently. This is because the lung’s cilia – tiny hair-like structures that move mucus, debris and germs – no longer work to clear the lungs.

A wet or “productive” cough means coughing up a lot of mucus.

A cough can also be dry or “unproductive”. This happens when the cough receptors in the airways, throat and upper oesophagus have become overly sensitised, triggering a cough even when there’s no mucus to clear.

Causes of a chronic cough

A cough is considered chronic when it lasts longer than eight weeks in adults, or four weeks in children.

The three most common causes are:

• post-nasal drip (where mucus drips from the back of the nose into the throat)
• asthma
• acid reflux from the stomach.

These often go together. One study found 23% of people with chronic cough had two of these conditions, and 3% had all three.

This makes sense – people prone to airway allergies are more likely to develop both asthma and hayfever (allergic rhinitis). Hayfever is probably the main cause of persistent post-nasal drip.

Meanwhile, prolonged, vigorous coughing can also cause reflux, possibly triggering further coughing.

Chronic cough is the primary symptom of two other conditions, although these can be more challenging to diagnose: cough-variant asthma and eosinophilic bronchitis. Both conditions inflame the airways. However, they don’t rapidly improve with ventolin (the standard clinic test to diagnose asthma).

Coughs after respiratory infections

Coughs can also persist long after a viral or bacterial infection. In children with colds, one systematic review found it took 25 days for more than 90% to be free of their cough.

After an infection, cough hypersensitivity may develop thanks to inflamed airways and over-responsive cough receptors. Even minor irritants will then trigger the coughing reflex.

The body’s response to infection makes the mucus more sticky – and more difficult for the overworked, recovering cilia to clear. Allergens in the air can also more easily penetrate the upper airway’s damaged lining.

This can trigger an unhelpful feedback loop that slows the body’s recovery after an infection. Excessive and unhelpful coughing tends to further fatigue the recovering cilia and irritate the airway lining.

Could I still have an infection?

When a cough persists, a common concern is whether a secondary bacterial infection has followed the first viral infection, requiring antibiotics.

Simply coughing up yellow or green phlegm is not enough to tell.

To diagnose a serious chest infection, your doctor will consider the whole picture of your symptoms. For example, whether you also have shortness of breath, worsening fever or your lungs make abnormal sounds through a stethoscope.

The possibility you have undiagnosed asthma or allergies should also be considered.

What treats a persistent cough?

People with a persistent cough who are otherwise healthy may request and be prescribed antibiotics. But these rarely shorten how long your cough lasts, as irritation – not infection – is the primary cause of cough.

The most effective treatments for shifting sticky mucus from the airways are simple ones: saline nose sprays and washes, steam inhalation and medicated sore throat sprays.

Honey has also been shown to reduce throat irritation and the need to cough.

The effectiveness of cough syrup is less clear. As these mixtures have potential side effects, they should be used with care.

Signs of something more serious

Sometimes, a cough that won’t go away could be the sign of a serious condition, including lung cancer or unusual infections. Fortunately, these aren’t common.

To rule them out, Australia’s chronic cough guidelines recommend a chest x-ray and spirometry (which tests lung volume and flow) for anyone presenting to their doctor with a chronic cough.

You should seek prompt medical attention if, in addition to your cough, you:

• cough up blood
• produce a lot of phlegm
• are very short of breath, especially when resting or at night
• have difficulty swallowing
• lose weight or have a fever
• have recurring pneumonia
• are a smoker older than 45, with a new or changed cough.

What if there’s no clear cause?

Very occasionally, despite thorough testing and treatment, a cough persists. This is called refractory chronic cough.

When no cause can be identified, it’s known as unexplained chronic cough. In the past, unexplained cough may have been diagnosed as a “psychogenic” or “habit” cough, a term which has fallen from favour.

We now understand that cough hypersensitivity makes a person cough out of proportion to the trigger, and that both the peripheral and central nervous systems play a role in this. But our understanding of the relationship between hypersensitivity and chronic cough remains incomplete.

These are disabling conditions and should be referred to a respiratory clinic or a chronic cough specialist. Speech pathology treatments may also be effective for refractory and unexplained coughs.

There are a class of new medications in the pipeline that block cough receptors, and seem promising for persisting, troublesome coughs.

David King, Senior Lecturer in General Practice, The University of Queensland

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

Not getting enough sleep is a common affliction in the modern age. If you don’t always get as many hours of shut-eye as you’d like, perhaps you were concerned by news of a recent study that found people who sleep less than six hours a night are at higher risk of type 2 diabetes.

So what can we make of these findings? It turns out the relationship between sleep and diabetes is complex.

The study

Researchers analysed data from the UK Biobank, a large biomedical database which serves as a global resource for health and medical research. They looked at information from 247,867 adults, following their health outcomes for more than a decade.

The researchers wanted to understand the associations between sleep duration and type 2 diabetes, and whether a healthy diet reduced the effects of short sleep on diabetes risk.

As part of their involvement in the UK Biobank, participants had been asked roughly how much sleep they get in 24 hours. Seven to eight hours was the average and considered normal sleep. Short sleep duration was broken up into three categories: mild (six hours), moderate (five hours) and extreme (three to four hours). The researchers analysed sleep data alongside information about people’s diets.

Some 3.2% of participants were diagnosed with type 2 diabetes during the follow-up period. Although healthy eating habits were associated with a lower overall risk of diabetes, when people ate healthily but slept less than six hours a day, their risk of type 2 diabetes increased compared to people in the normal sleep category.

The researchers found sleep duration of five hours was linked with a 16% higher risk of developing type 2 diabetes, while the risk for people who slept three to four hours was 41% higher, compared to people who slept seven to eight hours.

One limitation is the study defined a healthy diet based on the number of servings of fruit, vegetables, red meat and fish a person consumed over a day or a week. In doing so, it didn’t consider how dietary patterns such as time-restricted eating or the Mediterranean diet may modify the risk of diabetes among those who slept less.

Also, information on participants’ sleep quantity and diet was only captured at recruitment and may have changed over the course of the study. The authors acknowledge these limitations.

Why might short sleep increase diabetes risk?

In people with type 2 diabetes, the body becomes resistant to the effects of a hormone called insulin, and slowly loses the capacity to produce enough of it in the pancreas. Insulin is important because it regulates glucose (sugar) in our blood that comes from the food we eat by helping move it to cells throughout the body.

We don’t know the precise reasons why people who sleep less may be at higher risk of type 2 diabetes. But previous research has shown sleep-deprived people often have increased inflammatory markers and free fatty acids in their blood, which impair insulin sensitivity, leading to insulin resistance. This means the body struggles to use insulin properly to regulate blood glucose levels, and therefore increases the risk of type 2 diabetes.

Further, people who don’t sleep enough, as well as people who sleep in irregular patterns (such as shift workers), experience disruptions to their body’s natural rhythm, known as the circadian rhythm.

This can interfere with the release of hormones like cortisol, glucagon and growth hormones. These hormones are released through the day to meet the body’s changing energy needs, and normally keep blood glucose levels nicely balanced. If they’re compromised, this may reduce the body’s ability to handle glucose as the day progresses.

These factors, and others, may contribute to the increased risk of type 2 diabetes seen among people sleeping less than six hours.

While this study primarily focused on people who sleep eight hours or less, it’s possible longer sleepers may also face an increased risk of type 2 diabetes.

Research has previously shown a U-shaped correlation between sleep duration and type 2 diabetes risk. A review of multiple studies found getting between seven to eight hours of sleep daily was associated with the lowest risk. When people got less than seven hours sleep, or more than eight hours, the risk began to increase.

The reason sleeping longer is associated with increased risk of type 2 diabetes may be linked to weight gain, which is also correlated with longer sleep. Likewise, people who don’t sleep enough are more likely to be overweight or obese.

Good sleep, healthy diet

Getting enough sleep is an important part of a healthy lifestyle and may reduce the risk of type 2 diabetes.

Based on this study and other evidence, it seems that when it comes to diabetes risk, seven to eight hours of sleep may be the sweet spot. However, other factors could influence the relationship between sleep duration and diabetes risk, such as individual differences in sleep quality and lifestyle.

While this study’s findings question whether a healthy diet can mitigate the effects of a lack of sleep on diabetes risk, a wide range of evidence points to the benefits of healthy eating for overall health.

The authors of the study acknowledge it’s not always possible to get enough sleep, and suggest doing high-intensity interval exercise during the day may offset some of the potential effects of short sleep on diabetes risk.

In fact, exercise at any intensity can improve blood glucose levels.

Giuliana Murfet, Casual Academic, Faculty of Health, University of Technology Sydney and ShanShan Lin, Senior Lecturer, School of Public Health, University of Technology Sydney

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