COVID cough - How the virus has a lasting effect on the neural pathways in the brain

At the beginning of the pandemic, it was already apparent that coughing was one of the most common symptoms of COVID—the same is now true for the Omicron variant. The mostly dry cough from a COVID infection established supposed parallels with the seasonal flu. However, the COVID cough usually sets in shortly after the onset of the illness but does not often subside quickly. Thus, COVID cough is one of the most common symptoms of long-COVID.   So, which is the best cough medicine for COVID? Inhalation therapy with a nebulizer is one of the most effective (Post) COVID cough treatments for respiratory infections. It has been shown to reduce viral load, moisten mucus clusters and loosen stuck mucus. This form of therapy is recommended for both COVID cough, dry or wet. 

COVID: Cough as the most common COVID-19 symptom

COVID cough is one of the leading symptoms of the disease. According to surveys by the RKI, coughing occurred in 42 percent of people suffering from COVID-19. More recent data from the RKI show that with Omicron, coughing is the most common symptom (57 percent of those infected with the Omicron variant suffer from cough). The COVID dry cough is also a very common symptom in children. New research suggests that COVID-19 affects neural pathways in the brain that control the cough reflex. The damage seems to be persistent, which would explain why coughing can last for a long time after COVID and is also one of the leading symptoms of long COVID. Long COVID cough is therefore no longer caused by the disease itself infecting the respiratory system but is a so-called neurogenic cough, i.e., caused by irritation of nerves. It is not surprising that COVID can cause such a cough because it is now certain that COVID-19 is no ordinary respiratory tract infection. It also frequently causes neurological symptoms and lasting damage.

Why does COVID cause a cough?

Coughing is a natural reflex to clear the respiratory tract of germs, as well as harmful and foreign substances. If humans and other animals that have developed lungs could not cough, they would soon die of severe inflammation of the respiratory tract, or from an evolutionary point of view, would not have been able to develop. Special receptors in the respiratory tract react to invading foreign bodies, transmit the signals to the brain and trigger the cough reflex. "Reflex" here means that there is no free will about whether to cough or not. This is important because even with a neurogenic cough, increased self-discipline cannot improve the symptoms if the reflex is impaired due to nerve damage. COVID cough does not go away through willpower! Inflammation and swollen lymph nodes in the throat occur due to COVID infecting the respiratory tract. As a result, the tissue swells and produces fluid. This is detected by the receptors, which in turn trigger the cough reflex.

There may also be chest pain caused by coughing, as the frequent coughing after a COVID infection causes the chest muscles to tighten painfully.  

Omicron cough: Why does the symptom occur more frequently in the sub-variant?

Coughing is one of the typical Omicron symptoms and occurs even more frequently than in previous subvariants. A study from Norway showed that coughing occurs in 83 percent of Omicron cases. The reason Omicron causes coughing so frequently is that this sub-variant multiplies particularly quickly in the bronchial tubes (about 70 times faster than the Delta variant and the original wild strain). Omicron attacks the deeper parts of the lungs less frequently, which is why this variant causes severe pneumonia less often.

Inhalation therapy with inhalers could be the best cough medicine for COVID and containment of the spread of the virus in the upper and lower respiratory tract. The solution is applied directly to the mucous membrane of the respiratory tract and, according to studies, reduces the viral load by 72 percent. In addition, the mucous membranes are moistened, and their self-cleaning and natural barrier function is supported. 

COVID cough vs normal cough: What is a COVID cough like?

A study from 2021 shows that about two-thirds of people with COVID-19 had a COVID dry cough without mucus. COVID Cough with mucus during infection developed in only 33 percent of patients. Productive cough in COVID thus occurs in only half of those who developed a cough from COVID. The COVID dry cough is often associated with shortness of breath, which can increase to respiratory distress and require intensive care interventions. Some sufferers have also reported blood when coughing during a COVID infection.

COVID dry cough: What is the connection between irritable cough and shortness of breath?

How does the COVID dry cough sound? COVID cough, which is usually dry, can lead to a COVID sore throat and a barking, hoarse sound. A strong, dry cough often causes shortness of breath, even with other respiratory infections. However, a study conducted by the University Skin Clinic in Tübingen showed that COVID-19 infections also cause shortness of breath. Shortly after the infection, there is often a rapid and sustained production of a certain antibody (immunoglobulin A (IgA)). These antibodies belong to the body's immune system and are found in mucosal secretions as well as in the blood. On the mucous membranes, these antibodies act as protection against invading pathogens. The antibodies bind to other proteins in the mucosal secretions that are produced by the alveoli and are necessary for oxygen exchange. During COVID-19 infection, there is a deficit of this secretion due to the greatly increased levels of the IgA antibody, so the alveoli collapse and proper gas exchange in the lungs is no longer possible. The result is shortness of breath with a dry cough and below-average oxygen saturation (hypoxia).

For COVID dry coughs, isotonic saline solutions are the best cough medicine for COVID. These moisten the mucous membranes and cleanse them of viruses and bacteria.  

Wet cough COVID: Is there a secondary infection?

Wet cough during COVID indicates a secondary infection with bacteria. COVID cough with yellow mucus during a COVID infection is a sure sign of an additional bacterial infection, where the mucus can sometimes become greenish. But how does the wet cough during COVID sound? The sound of the wet cough during COVID also changes, rattling noises in the bronchial tubes are typical, which is often audible to others. Those affected also increasingly report bacterial tonsillitis during COVID. A warning sign is a steady worsening of the condition, especially if new symptoms appear, such as severe pain in the chest when coughing during or after COVID infection, high fever, and palpitations, or the shortness of breath continuing to worsen. Blood in the sputum is also a clear warning sign. Since the body is already weakened by COVID-19, there is a danger that bacteria can multiply unhindered in the respiratory tract and a life-threatening bacterial pneumonia can develop. In this case, urgent medical attention is required.

In the case of a productive cough during COVID, an inhalation solution with the active substance ambroxol is the best wet cough medicine for COVID. The inhalation solution loosens the mucus in the bronchial tubes and relieves the irritation from the cough. 

Can there be blood when I cough during COVID?

Coughing up blood is a rare COVID cough symptom and occurs in about one to five percent of people with the disease. This is called hemoptysis and is usually associated with the sputum when pneumonia develops, or a pulmonary embolism occurs. Blood when coughing during a COVID infection is a very serious symptom and should be checked on with a doctor.

Long-COVID: Why does the lingering cough persist after COVID?

Many people who were previously ill and have since recovered complain of a post COVID cough that lasts for many weeks or even months. Thus, many people are unsure and ask themselves, "How long does COVID cough last?". A study published in The Lancet Respiratory Medicine found that people with COVID cough for an average of 19 days. In five percent of cases, the post COVID cough lasts up to four weeks. About 2.5 percent of people formerly infected with COVID-19 still suffer from the post COVID cough after one year. Studies have shown that the body's immune system is still much more active months after infection than before. The overactive immune response, which does not calm down, can cause the lingering cough after COVID, in addition to damaging the nerve pathways responsible for the cough reflex. A British study showed that inflammation of the respiratory tract can occur weeks after the actual symptoms of COVID-19 have subsided, causing the typical signs of illness such as shortness of breath and a persistent irritating cough after COVID. Due to these persistent inflammations, coughing with mucus after a COVID infection is not uncommon. The so-called "post-viral cough" can last up to two months. Due to this structural change of the tissue, mucous post COVID cough is not uncommon. Furthermore, a study by the Charité hospital in Berlin found that hyperventilation, i.e., particularly deep breathing combined with an increased respiratory rate, can also be a cause of long-COVID. Typically, the post COVID cough occurs more frequently during physical exertion (exertion respiratory distress) and when breathing cold air.

COVID symptoms in vaccinated persons: Cough as a vaccine reaction

One of the common COVID symptoms in vaccinated people is dry cough after COVID vaccine as a vaccine reaction, which occurs in about 10 percent of vaccinated people. It is known that because of the immune response, COVID symptoms in vaccinated people such as lingering cough, but also headache and sore throat, can occur after COVID vaccination. If dry cough after COVID vaccine occur in vaccinated persons, this is no cause for alarm, but is an expected side effect of the vaccination.  

COVID cough: How to get rid of COVID cough?

The lingering cough after COVID (or Long Covid Cough) is extremely distressing for many sufferers. So, what could be the best cough medicine for COVID? Initial success in relieving the lingering cough after COVID, as well as reducing the viral load in COVID, has been achieved through inhalation therapies for both COVID coughs, whether dry or wet. This usually involves the use of a saline solution with varying salt content depending on the type of cough. The aim of these therapies is to clear the airways and to calm and moisten them. This is important in (Post) COVID cough treatment because coughing with phlegm is common after a COVID infection. Drinking large amounts of fluids can also be helpful for lingering coughs after COVID, as sufficient fluid intake can liquefy stuck mucus, making it easier to cough up afterwards. It is important not to deliberately suppress the cough, as this will prevent the necessary excretion of mucus. It is worth mentioning that many elderly people die of pneumonia mainly because they are physically too weak to use vigorous coughing to clear their airways of mucus and other foreign bodies. So how long does COVID cough last after infection? It depends on one's own behavior and the use of therapies. COVID cough does not go away by suppressing the body's own defense mechanisms. Since coughing is a very common symptom of COVID and virus particles are released into the environment when coughing, it is essential to observe good hygiene both when coughing and when sneezing.